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Collection  de 
microfiches. 


Canadian  Institute  for  Historical  Microreproductions  Institut  Canadian  de  microreproductions  historiques 

1980 


Technical  Notes  /  Notes  techniques 


The  Institute  has  attempted  to  obtain  the  best 
original  copy  available  for  filming.  Physical 
features  of  this  copy  which  may  alter  any  of  the 
images  in  the  reproduction  are  checked  below. 


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Coloured  covers/ 
Couvertures  de  couleur 


Coloured  maps/ 

Cartes  g6ographiques  en  couleur 


Pages  discoloured,  stained  or  foxed/ 
Pages  Jtcoior^es,  tachet^es  ou  piqu6es 


Tight  binding  (may  cause  shadows  or 
distortion  along  interior  margin)/ 
Reliure  serrd  (peut  causer  de  I'ombre  ou 
de  la  distortion  le  long  de  la  marge 
intdrieure) 


L'Institut  a  microfilm6  le  meilleur  exemplaire 
qu'il  lui  a  6t6  possible  de  se  procurer.  Ce:tains 
dtfauts  susceptibles  de  nuire  A  la  quality  de  la 
reproduction  sont  notte  ci-dessous. 


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Pages  endommagdes 


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Bibliographic  Notes  /  Notes  bibliographiques 


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Bound  with  other  material/ 
Reli6  avec  d'autras  documents 


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Erreurs  de  pagination 


Pages  missing/ 
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Cc  mmentaires  suppKlmentaires 


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The  images  appearing  here  are  the  best  quality 
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of  the  original  copy  and  in  keeping  with  the 
filming  contract  specifications. 

Les  images  suivantes  ont  M  reproduites  avec  le 
plus  grand  soin,  compte  tenu  de  la  condition  at 
de  la  nett<9t«  dj  I'exempialre  film6,  et  en 
conformity  avec  les  conditions  du  contrat  de 
filmage. 

The  last  recorded  frame  on  each  microfiche  shall 
contain  the  symbol  —^  (meaning  CONTINUED"), 
or  the  symbol  V  (meaning  "END"),  whichever 
applies. 

Un  des  symboles  suivants  apparaTtra  sur  la  der- 
nidre  image  de  cheque  microfiche,  selon  le  cas: 
le  symbols  — ^  signifie  "A  SUIVRE",  le  symbols 
y  signifie  "FIN". 

The  original  copy  was  borrowed  from,  and 
filmed  with,  the  Icind  consent  of  the  following 
institution: 

L'exemplaire  filmA  fut  reproduit  grAce  it  la 
g6n«rosit6  de  l'6tablissement  prAteur 
suivant : 

Library  of  the  Public 
Archives  of  Canada 

La  bibliothique  des  Archives 
publiqu^s  du  Canada 

'  .<.■>':. 

Maps  or  plates  too  large  to  be  entirely  included 
in  one  exposure  are  filmed  beginning  in  the 
upper  left  hand  corner,  left  to  right  and  top  to 
bottom,  as  many  frames  as  required.  The 
following  diagrams  illustrate  the  method: 

Les  cartes  ou  les  planches  trop  grandes  pour  Atre 
reproduites  en  un  seul  clich6  sont  fiimies  A 
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BULLETIN  OF  THE  GEOLOGICAL  SOCIETY  OF    AMERICA 

Vol.  6.  pp.  117-146 


^S 


GEOLOGICAL  NOTES  ON  SOME  OP  THE  COASTS  AND 
ISLANDS  OF  BERING  SEA  AND  VICINITY 


Br 


GEORGE  M.  DAWSON 

ASSISTANT  DIRECTOR  OF  THE  GEOLOGICAL  BURVBy  OF  CANADA 


ROCHESTER 

PUBIJSHED  BY  THE  SOCIETY 

February,  1894 


^«i;ujWHHli;«<'ji  |(,  I  ii,iiiij|i|ip)ipiHMpipiippp 


BULLETIN    OF    THE    GEOLOGICAL    SOCIETY    OF    AMERICA 
Vol.  5,  pp.  ii7-i4«  February  2,  i894 


GEOLOGICAL  NOTES  ON   SOME   OF  THE  COASTS   AND 
ISLANDS  OF  BERING  SEA  AND  VICINITY 

BY   GKORGe"  M.    DAWSON 
'  ,  ASSISTANT  DIRECTOR  OP  THE  GEOLOGICAL  SURVEY   OP  CANADA 

(Read  before  the  Society  December  27,  189S)    -^   , 

.  CONTENTS 

P»ge 

Introduction 117 

Aleutian  Inlands 119 

Akutan  lHlan<l 119 

Unalaska  Island 120 

Atka  Island 120 

(ireat  Sitkin  Island 121 

Buldir  Island 121 

Semichi  Islands 121 

Attn  Island 122 

Commander  Islands 123 

Bering  Island 124 

Copper  Island 12($ 

Kamchatka 127 

Pribilof  Islands 130 

Nunivak  Island 133 

Cape  Vancouver 134 

Saint  Matthew,  Hall  an<l  Pinnuclc  Islands 135 

Saint  Lawrence  Island 138 

Plover  Bay 140 

General  Remarks 143 


Introduction. 


The  notes  here  i)resented  are  tliose  made  during  an  extended  cruise  in 
the  Bering  sea  region  during  the  summer  of  1891.  The  writer  was  at  the 
time  more  particularly  engaged  in  the  investigation  of  matters  connected 
with  the  fur-seal,  as  one  of  the  British  ciimmissioners  ajjpointed  for  that 
purpose,  hut  his  somewhat  prolonged  familiarity  with  the  geological  feat- 
ures of  British  Colunihia  and  adjacent  parts  of  northwestern  (-anada 
caused  him  to  feel  a  s])ecial  interest  in  the  corresponding  features  of  the 

XVI-BuLi.  Oeoi,.  Soc.  Am.,  Vol.  Ti,  18»3.  (117) 


118 


G.  M.  DAWSON COASTS    OF    BERINO    SEA    AND    VlflN'ITY. 


various  places  visited.  Tlie  time  available  for  observations  ashore  was 
usually  very  limited,  ami  tluis,  but  for  the  facit  that  so  little  is  yet  known 
res[)eeting  the  geology  of  the  whole  region,  such  notes  as  it  was  possible 
to  make  would  possess  very  little  inherent  value.  As  it  is,  they  may  be 
accepted  as  a  slight  contribution  to  our  knowledges  of  a  portion  of  the 
globe  of  which  but  a  few  limited  spots  have  yet  come  under  the  observa- 
,  y^  tion  of  any  trained  geologist. 

Dr  W.  H.  Dall  has  lately  collected  in  a  single  work  a  ])recis  of  nearly 
all  the  authentic  data  relating  to  the  American  shores  and  islands  of 
Bering  sea.*  This  work  is  devoted  specially  to  the  Neocene  formations, 
but  these  include  a  great  part  of  those  known  to  occur,  and  references 
are  besides  given  in  it  to  various  older  formations.  Allusion  is  fretjuently 
made  to  this  work  of  Dr  Dall's  in  the  secjuel,  and  in  so  far  as  they  cover 


Figure  l.—Map  of  Coasts  and  Islands  of  Bering  Sea. 

the  same  ground  the  notes  here  set  down  may  be  regarded  as  merely 
supplementary  to  those  he  has  pul)lished  either  as  the  result  of  his  own 
observations  or  in  the  form  of  extracts  from  older  works.  Thus  in  what 
follows  respecting  the  Aleutian  islands,  it  will  l)e  found  that  only  those 
touched  at  or  seen  by  the  writer  are  mentioned,  and,  generally  speaking, 
that  greater  attention  is  given  to  ])laces  al)0Ut  which  the  known  facts  are 
l)articul,\rly  scanty  or  altogether  wanting,  and  to  those  more  general 
l)hysiographic  features  oi'  the  land  to  which  the  attention  of  the  earlier 
explorers  was  not  directed. 

Mr  W.  F.  Ferrier,  lithologist  to  the  Geological  Survey  of  Canada,  has 
been  so  kind  as  to  look  over  the  rock  specimens  brought  back,  and  in 
some  cases  has  examined  them  microscopically  in  thin  sections  for  the 
l>urpose  of  their  determination.  '  •  • 

*Biill.  U.  S.  GeoluKical  Survey,  no.  84, 1892,  p.  234  et  aeq. 


H": 


»'5IL,. 


AKUTAN   ISLAND. 


110 


Aleutian  Islands. 

Ahitan  Maud. — The  south  side  of  this  iHland  was  tho  firat  part  of  tlie 
Alputian  rliain  sijjhtod  by  us  in  ai)i)r()a('bing  Bering  Hca.  It  is  character- 
ized l)y  rugged  and  bold  cliff's,  broken  into  stacks  and  pinnacles  at  the 
})oints,  but  between  retiring  into  coves  and  bays,  from  some  of  which 
rather  wide  valleys  run  inland.  The  varied  and  often  strongly  contrast- 
ing coloring  of  the  weathered  rocks  in  these  cliffs,  together  with  the  abso- 
lute treelcssness  of  the  land  and  the  vivid  green  of  the  sward  and  herbage 
with  which  it  is  covered  when;ver  not  too  rocky  or  too  elevated  for  any 
growth,  were  the  most  striking  features.  These,  however,  are  almost 
equally  found  in  all  the  islands  of  the  Aleutian  chain. 

Steej)  and  irregular  hills  and  ridges  rising  from  the  shores  culminate 
in  the  central  part  of  the  island  in  mountains  sufficiently  higl:   to  carry 


J 


Itic/.ijiwi  Beds 
FletnJcs  of  Old  f.'arui. 


FiQVRi  1.— Diagram  il 


FlMUBeds  irv  Cliff^s. 

:■  (7  the  Structure  of  the  northern  Part  o/Akittan  Iiland. 


much  snow  in  these  latitu.iv  •  the  year  round.  The  north  side  of  this 
island  was  afterward  seen  under  favorable  (^oiiditions  of  weather,  and 
the  island  as  a  whole  apyjears  to  represent  the  denuded  remnants  of  a 
single  great  volcanic  center.  The  original  focus  of  eruption  seems  to  have 
been  situated  to  the  west  of  the  middle  of  the  island.  Somewhat  nearer 
the  actual  center  of  the  island  a  little  cloud  of  steam  still  issues  from  one 
of  the  higher  points,  and  occasional  small  eruptions  have  been  noted.* 

The  eastern  portion  of  the  island  shows  j)art  of  the  lower  slope  of  the 
original  great  volcanic  cone,  the  l)eds  flattening  out  gradually  to  the  ea.st- 
ward  in  conformity  with  the  decreasing  slope  of  the  surface. 

The  antiquity  of  the  volcanic  action  to  which  the  island  as  a  whole 
owes  its  origin,  is  shown  by  the  amount  of  the  subsequent  effect  of  denuda- 
tion upon  it.  The  deep  valleys  have  evidently  been  cut  out  by  ordinary 
subaerial  erosion  during  a  prolonged  period  of  waste,  and  many  of  the 


*  Alaska  and  its  ReBourees:  DnII,  pp.  467,  470. 


w>i^^-.'^  ...... ■,j!t \i:x 


120 


(i.  M.  T»AWS(>N^"OAST8   OK    JUCKING    SKA    AND    VICINITY. 


lower  rid^ri'H  siikI  hill.s  owe  their  ])rc'Hont  t'orni.s  entirely  to  wueh  action 
The  iteripherai  parts  of  the  island  have  during  the  same  period  been 
much  reduced  and  cut  back  by  the  sea. 

The  ditts  along  the  south  shore  and  those  altout  the  middle  of  the 
north  sbore  dis])lay  l>edding,  wbieli  in  the  planes  of  section  ap}tears  nearly 
horizontal.  The  individual  beds  are  for  the  most  part  thick,  and  some 
of  them  show  a  i)rononnced  basaltic  structure. 

Unalaska  Maud. — Respecting  the  island  of  Unalaska  little  can  be  added 
to  the  notes  lately  brouglit  together  by  Dr  Dall.*  A  good  view  was  ob- 
tained of  that  i)art  of  the  north  coast  between  ^lakushin  and  Captain's 
bays,  behind  which  rises  Makusbin  volcano,  the  highest  mountain  (5,474 
feet)  on  the  island.  The  upper  parts  of  this  mountain  and  the  bigh 
ridges  about  it  were  deeply  covered  with  snow  in  August,  and  small, 
irregular  glacier  masses,  more  or  less  crevassed,  were  observed  lierc  and 
there.   . 

Makusbin  is  not  a  tj'pical  volcanic  cone,  but  an  irregular,  lumpy 
mountain  mass  witb  some  rather  bold  spurs  and  crests  even  about  its 
upi)er  parts,  which  seem  to  evidence  considerable  waste  by  denudation 
since  tbe  latest  important  eruptions.  A  cloud  of  white  steam  still,  how- 
ever, hangs  about  its  summit.  The  natural  processes  of  waste  have  not 
acted  sufficiently  long  upon  this  island  to  produce  rounded  forms  or 
light  slopes.  The  hills  are  generally  shari)  edged,  peaked  and  bold,  but 
often  covered  with  herbage  nearly  to  their  tops. 

The  shore-cliffs,  from  abreast  of  Makusbin  to  Captain's  harbor,  show 
horizontal  or  slightly  inclined  bedding,  which  is  rather  too  fine  and  uni- 
form to  be  explained  as  that  of  sui)erpo3ed  lava  flows.  The  beds  ex- 
posed probably  consist  of  scoria  or  volcanic  ash  deposited  under  water- 
Dall  notes  the  occurrence  of  marine  Miocene  dej)osits  in  Makusbin  bfty.f 

The  slopes  and  hills  about  Captain's  harbor  were  all  closely  scanned 
for  evidence  of  old  beachlines,  but  none  were  seen.  There  appears  to 
have  been  no  notable  upward  movement  of  this  land  since  the  denuda- 
tion which  produced  its  present  form  took  place.  The  little  flat  about 
the  village  of  Unalaska  is  composed  of  gravel  covered  with  black  soil, 
and  is  about  twenty  feet  above  high-water  mark.  Its  occurrence  might 
almost  be  ex{)lained  as  a  beach  deposit  at  the  present  storm  level,  but  it 
more  probably  indicates  a  ver}'^  slight  rise  of  the  land. 

Atka  Island. — A  call  was  made  at  Nazan  bay,  on  the  east  side  of  Atka 
island.  This  island,  with  others  near  it  which  were  more  or  less  imper- 
fectly seen,  appears  to  be  practically  entirely  composed  of  volcanic  rocks. 
Some  interesting  notes  on  Atka  are  given  by  Dall  in  the  publication 


*  Op.  cit.,  p.  242. 

t  Op.  clt.,  p.  24;i.     In  .iddition  to  tho  voloanin  rocks  of  vnrioH.s  kinds,  Dall  mentions  thn  occur- 
rence of  granite  or  syenite  [gabbro  ?]  in  the  interior  of  this  island.    Op.  elt.,  pp.  233,  242. 


ATKA    ISLAND    AND   OTHKRS   TO   THE    WESTWARD. 


121 


already  (juotod  (pagcH  248-244),  from  wliich  it  appeaix  that  in  Karovinski 
bay,  on  tho  west  side  of  the  island,  jtienes  of  fossil  wood,  sometimes  ailici- 
fied,  as  well  as  marine  Miocene  fossils  in  tuttaceous  volcanic  deposits,  are 
found.  The  little  islands  in  Nazan  haj'  and  the  low  projecting  i)<)ints 
ahout  it  have  a  basaltic  appearancjc  and  rather  irregular  columnar 
structure.  The  rock  showing  on  the  beach,  at  the  village,  is  a  greenish 
gray.  Hue  grained  material,  very  hard  and  in  j)lace8  containing  many 
grains  of  iron-|)yrites,  probably  clastic  and  apparently  a  diabase,  though 
not  microscoi)ically  determined.  It  is  also  traversed  by  small  drusy 
veins  of  quartz,  and  large  loose  masses  of  quartz  were  found  which  had 
evidently  not  travelled  far. 

In  a  small  brook,  which  has  cut  out  a  little  ravine  near  the  village,  a 
considerable  dei)th  of  superficial  earthy  material  is  exposed.  This  ex- 
hibits a  certain  amount  of  stratification  jiarallel  to  the  slope  of  the 
ground.  It  is  brownish  or  reddish  brown  in  color,  and  ai>peared  to  be 
composed  of  volcanic  detritus,  which  has  either  been  deposited  in  the 
sea  when  the  land  was  at  a  s(micwhat  lower  level,  or  perhaps  more 
])robably  merely  wa.shed  down  the  slopes  while  in  an  incoherent  and 
fresh  state.  Material  of  the  same  kind  was  recognized  elsewhere  on 
this  and  other  islands  of  the  Aleutian  chain,  sometimes  in  rather  notable 
tjuantity. 

No  indications  of  old  terrace  levels  were  observed  about  Nazan  bay, 
but  around  the  base  of  the  mountain  which  forms  a  projecting  i)oint  to 
the  north  of  the  entrance  of  the  V)ay,  three  or  more  successive,  indistinct 
terrace-like  markings  occur,  the  highest  being  at  an  elevation  of  about 
1,000  feet  above  the  present  sea  level.  These  markings  may  represent 
old  beachlines  im])ressed  in  soft  material,  but  from  their  indefinite 
character  this  remains  uncertain. 

Great  Sitkin  Island. — After  jiassing  Atka  island  a  fine  general  view  of 
Great  Sitkin  island  was  obtained.  This  evidently  consists  of  a  single 
large  volcanic  cone,  which,  according  to  the  charts,  is  still  5,033  feet  high. 
Its  upi)er  portion  was  heavily  covered  with  snow. 

Biildir  Island. — Buldir  island  was  passed  sufficiently  near  to  enable 
it  to  be  well  seen.  Its  eastern  end  is  most* elevated,  and  high  cliffo  there 
show  a  series  of  flows  or  beds  of  volcanic  material,  dipping  rather  steeply 
we.'<tward.  The  angle  of  dij)  gradually  diminishes  and  the  stratification 
becomes  horizontal  at  the  west  end  of  the  island,  the  general  height  of 
the  surface  decreasing  in  a  corresponding  degree.  The  whole  island 
clearly  represents  the  residual  portion  of  an  originally  symmetrical  vol- 
canic mountain,  the  greater  i)art  of  which  has  been  cut  away  by  the  sea. 

Semlchi  Islands. — The  Semichi  islands  form  a  narrow  chain,  broken  by 
two  small  gaps,  and  about  fourteen  miles  in  total  length.    They  are  un- 


122 


O.  M.  DAWSON — COASTS   OF    BEKING   SEA    AND    VICINITY. 


usually  low  and  flat,  tho  Inglioht  point,  at  the  woHtorn  end,  being,  accord- 
ing to  tho  chart,  about  8()()  feet.  The  islands  slope  down  to  the  south- 
ward with  nearly  uniform  grassy  surfaces. 

Attn  Idand. — Tliis  is  tin;  wcstorinnost  island  of  tiie  Aleutian  chain.  It 
appears  to  be  throughout  mountainous,  and,  in  its  general  contour,  with 
steep,  grassy  elevations,  closely  set,  is  not  unlike  most  of  the  larger  islands 
of  the  chain.     Its  highest  point,  according  to  the  chart,  is  3,()!S4  feet. 

My  observation.^  were  confined  to  the  vicinity  of  Ohichagof  harbor,  on 
the  north  side  of  the  island.  At  the  cast  end  of  tlie  gravelly  beach  at 
the  bottom  of  the  harbor,  hard,  greenish  gray  rocks  occur,  possibly  dia- 
base in  composition,  l)ut  too  fine  grained  for  nincroscopic  determination. 
These  are  in  some  places  distinctly  bedded  and  probably  clastic,  the  dip 
being  north  65°  west  (magnetic),  at  an  angle  of  4o°.  Similar  rocks,  with 
a  similar  dip,  appear  on  the  opi)osite  siile  of  the  harbor  at  the  west  end 
of  the  same  gravel-beach,  and  were  again  found  at  the  summit  of  the 
mountain  or  high  ridge  on  the  east  side.  The  rocks  of  Gibson  island,  ott' 
the  mouth  of  the  harbor,  were  observed  to  be  bedded  with  such  unusual 
regularity  that  this  island  was  specially  visited.  They  proved  to  consist 
for  the  most  part  of  much  altered  and  indurated  volcanic  materials,  with 
purplish,  greenish  and  gray  colors.  Perhaps  the  most  abundant  material 
is  a  medium  grained  rock,  which  in  some  specimens  is  evidently  an  erup- 
tive, in  others  i)robal)ly  clastic,  and  very  po.ssibly  a  diabase  in  composi- 
tion, but  fine  grained  clastic  fels{)athic  rocks  also  occur,  which  pass  into 
a  black  compact  material  which  is  ajiparently  a  true  argillite.  Though 
sought  for,  no  fossil  remains  of  any  kind  could  be  found.  The  dip  is 
here  north  30°  east  (magnetic),  at  an  angle  of  40°. 

The  rocks  seen  in  the  harbor  closely  resemble  those  noted  in  Nazan 
bay,  Atka  island.  The  general  lithological  character  and  degree  of  altera- 
tion of  the  rocks  of  this  i)art  of  Attn  island  resenddes  that  of  some  of  the 
Mesozoic  rocks  of  British  (-ohunbii,  particularly  i)arts  o^  the  Triassic 
series  as  represented  there,  and  though  such  a  critt^rion  is  of  very  linnted 
value,  Hall  may  not  improbably  be  correct  in  his  conjecture  that  they 
a*re  of  Mesozoic  age.*  In  any  case,  the  high  angles  at  which  these  rocks 
lie  and  the  amount  of  alteration  and  denudation  which  they  have  suf- 
fered show  that  beds  much  older  than  those  referal)le  to  modern  or  even 
late  Tertiary  volcanic  action  are  included  in  the  composition  of  this  ])art 
of  the  Aleutian  chain. 

Dr  Dall  states  that  Attn  is  destitute  of  modern  volcanic  rocks,  and  my 
observations,  so  far  as  they  go,  are  to  the  same  eifect.     Even  in  the  gravel 

•Op.  cit.,  p.  .'144.  Tli«  ocfiiirrenoe  of  Triassic  rooks  i:i  the  peninsulii  of  Aliiska  is  Indicated  liy 
specimens  from  that  peninsula  shown  to  me  by  ts.t  R.  Neumann,  of  Unalasku.  These  consist  of 
t.ie  MonotiH-bearing  urgillitt*  of  that  formation. 


COMMA NDKR    ISLANDS. 


128 


of  till'  l)ea('ho8  HUch  rocks  appear  to  be  wanting.  The  pehhlen  connint 
chiefly  of  materials  like  those  olwerved  to  occur  locally,  hut  a  considera- 
hle  nuiuher  of  f^ray  granitoiil  fragiuj'nts  were  also  ohserved  along  the 
shores,  of  which  the  origin  is  uncertain.  It  is  noteworthy  that  though 
this  island  thus  appears  to  he  conipiwc'l  of  older  rocks  than  most  of  the 
Aleutians,  its  to|)ograpluc  forms  are  not  dissimilar  from  those  of  the 
other  islands.  No  distinguishing  features  are,  for  example,  apparent 
between  the  hills  surrounding  Chichagof  harbor  and  tho.se  near  Captain's 
harbor  in  llnalaska. 

About  Chichagof  harbor  there  arc  some  well  marked  old  seaclilfs  rising 
behind  gravelly  Hats  of  twenty  or  thirty  feet  in  height,  and  such  as  to 
indicate  an  elevation  of  the  land  by  that  amount  since  their  formation. 
On  the  slojjcs  of  the  ridge  on  the  west  side  of  the  ha rlior,  .several  faintly 
Impressed  horizontal  lines  also  appear,  the  highest  l)eing  about  800  feet 
above  the  sea.  They  seem  to  represent  incipient  terraces,  and,  if  so,  must 
indicate  a  somewhat  rapid  elevation  of  the  land,  sui-h  as  to  prevent  any 
long  continued  marine  action  at  any  particular  level. 


dip  is 


Commander  Islands. 

Bering  and  Copper  islands,  with  a  few  adjacent  rocks  and  reefs  of  no 
importance,  form  the  Komandorski  or  Connnander  gnmp  appurtenant 
to  Russia  and  subsidiary  to  the  goviTument  of  the  Anmr.  The  two 
islands  are  parallel  in  trend,  lying  in  northwest  by  southeast  b(>arings. 
Tliey  are  separated  at  their  nearest  points  by  a  dist^mce  of  26  nautical 
miles.  Copper  island,  which  lies  farthest  to  the  eastward,  is  divided  by 
1!)0  miles  of  deep  ocean  from  Attn,  the  easternmost  of  the  Aleutian 
chain,  while  Bering  island  is  distant  some  \)r>  miles  from  the  nearest  part 
of  the  peninsula  of  Kamchatka.  The  high  volcanic  mountains  of  the 
peninsula  may  in  clear  weather  be  seen  from  Bering  island,  l)Ut  the  latter 
is  proliably  never  imder  any  circum.stances  visible  from  the  mainland. 
In  view  of  the  fact  ihat  the  Aleutian  islands  were,  when  discovered, 
rather  thickly  iidiabited,  and  that  evidences  exist  on  them  of  inhabitants 
long  antecedent  to  hi,storic  times  for  the  region,*  it  is  somewhat  remark- 
able that  the  Commander  islands  ap|)car  never  to  have  been  visited  by 
man  ))revious  to  their  di.scovery  by  the  Uu.'^sians  in  1741.  The  climate 
of  these  islands  is  humid  and  cool,  insuring  a  luxuriant  growth  of  grasses 
and  herbaceous  jdants  of  various  speciej  wherever  there  is  sufficient  soil, 
but  though  less  rigorous  than  that  of  the  lands  in  similar  latitudes  on 
the  eastern  side  of  Bering  sea,  no  trees  or  shrubs  are  anywhere  found 
upon  them. 

•Dull  in  ContribiitlotiB  to  North  American  Ethnology,  vol.  i. 


'f 


124 


a.  M.  DAWSON — COASTS   OF    niCUIXO   SKA    AND    VICINITY. 


I': 


Bering  Maud. — leering  island  is  about  50  miles  in  extreme  length,  with 
a  width  of  nearly  2U  miles  at  its  northern  and  wider  end.  From  this 
it  narrows  gradually,  hut  irregularly,  to  caj)e  Maniti,  its  southeastern  ex- 
tremity. The  northern  half  of  the  island  is  low,  with  a  rolling  or  nearly 
fiat  surface,  much  of  which  is  described  as  consisting  of  "tundra"  land. 
It  includes  one  large  lake,  which  discharges  on  tlie  north  shore.  The 
southern  half  is  higher,  and  appears,  as  seen  from  the  sea,  to  consist  of  a 
mass  of  rounded  hills,  varying  in  height  from  several  hundred  to  perhaps 
1,000  feet.  There  arc  no  harbors  alxmt  the  island,  l)ut  a  fair  anchorage, 
with  off-shore  winds,  may  be  found  in  a  bay  at  Niivolski,  on  the  west 
coast  of  the  island,  about  ten  miles  from  its  northern  end.  The  only 
permanent  settlement,  with  the  head(iuarters  of  the  Russiiin  government 
of  the  islands,  is  situated  at  this  place. 

The  shores  of  the  higher  southern  i)ortion  of  the  island  are  ^'enerally 
bordered  by  cliffs  or  steep  scarped  banks,  with  narrow  and  V-8li''^P6d 
valleys  breaking  through  them  to  the  sea. 

On  the  east  side  of  cape  Maniti,  and  for  some  miles  northward,  regu- 
larly stratified  rocks  in  rather  thin  l)eds  of  pale  brownish  colors  were 
observed,  dipping  regularly  northward  at  an  angle  of  about  15°.  Farther 
to  the  northwestward,  along  the  same  eastern  coast,  at  cape  Tolstoi  (thir- 
teen miles  from  cape  Maniti)  paler  fawn-colored  or  cream-colored  beds 
were  seen,  dipping  away  from  the  shore  at  low  angles.  They  are  crum- 
bling and  incoherent  in  character,  and  produce  long  slopes  of  debris  in 
some  places  between  the  bluffs  and  the  sea.  Similar  rocks  apparently 
continue  from  cape  Tolstoi  to  Stareya  bay,  at  a  further  distance  of  nine- 
teen miles,  but  the  cliffs  become  lower  and  the  scarped  banks  are  less 
steep. 

A  landing  Avas  effected  at  Stareya  bay,  when  it  was  found  that  the 
scarped  slopes,  which  often  resemble  sand  from  a  distance  and  are  so 
described  in  sailing  directions,  are  in  reality  composed  of  angular  and 
rubbly  fragments  of  whitish,  yellowish  and  gra}'  argillites  or  shales,  with 
crumbling  sandstones  and  argillaceous,  fine  grained  gray  limestones. 
All  these  rocks  are  well  bedded,  and  on  some  surfaces  small  carbona- 
ceous plant  fragment^  were  observed,  though  none  of  these  were  deter- 
minable. The  material  of  the  Ijeach  is  composed  almost  entirely  of  the 
debris  of  similar  rocks,  and  it  is  prol)ablc  that  the  whole  northeastern 
coast  of  the  island,  at  least  this  ftxr,  consists  of  moderately  indurated 
sediments  of  Tertiary  age,  regularly  bedded  and  present  in  considerable 
or  great  thickness.  The  browner  beds  of  tlie  vicinity  of  cape  Maniti 
may,  however,  be  tuifaceous  volcanic  material.  While  it  is  not  improb- 
able that  basaltic  or  other  volcanic  rocks  may  also  occur,  as  some  such 
were  found  upon  the  shore,  they  were  not  actually  seen  in  place.     No 


BERING   ISLAND. 


125 


,  with 
11  this 
rn  ex- 
iiearly 
'  land. 
,    The 
ist  of  a 
erhaps 
lorage, 
le  west 
e  only 
rnment 

merally 
■shaped 

d, regu- 
)rs  were 
Farther 
,oi  (thir- 
red  beds 
re  cruni- 
lebria  in 
pavently 
of  nine- 
are  less 

that  the 
are  so 
jlar  and 

es,  with 
iiestones. 
carbona- 

re  deter- 

y  of  the 
th  eastern 
ndurated 
siderable 
Maniti 

iniprob- 
)iiie  such 

aoe.     No 


>c 


crystalline  or  other  evidently  foreign  rocks  were  found  upon  the  beaches. 
The  soil  in  the  valleys  and  on  the  lower  slopes  of  the  hills  is  a  reddish, 
fine  grained  material,  doubtless  formed  by  the  disintegration  of  the  rocks 
above  described. 

No  satisfactory  general  views  of  the  coastline  of  the  northern  and 
lower  jiart  of  Bering  island  were  obtained  on  account  of  foggy  weather. 
A  landing  was,  however,  made  on  the  north  shore  at  capo  Yushin,  where 
tbe  "  north  rookery  "  is  situated.  Tiie  shore  is  here  rocky,  and  Avide, 
low  reefs  run  out  from  it,  entirely  comi)osed  of  volcanic  rocks.  One  of 
these  is  a  dark  brown  melaphyre,  containing  plagiocUise,  augite  and 
olivine  crystals,  with  some  magnetite,  embedded  in  a  groundmass  of  the 
same  constituents.  There  is  also  a  fragmental  rock  of  somewhat  peculiar 
apjieai'ance,  which  seems  not  to  ])e  a  true  agglomerate,  but  an  eruptive 
material  charged  with  fragments  of  dissimilar  rocks.  The  basis  is  some- 
what amygdaloidal,  and  may  ver\'  ])robably  have  the  same  composition 
as  tbe  rock  first  noted.  \\'ell  formed  jjyroxene  crystals  are  abundant  in 
some  parts  of  the  mass.  The  rocks  are  much  shattered,  and  it  was  not 
easy  to  determine  the  precise  relations  of  the  two  varieties  here  associated. 
No  trace  of  sedimentary  rocks  like  those  of  Htareya  was  seen. 

At  Nikolski,  on  the  west  side  of  the  island,  the  point  south  of  tbe  little 
])iiy  is  composed  of  hard,  fine  grained,  gray,  augite-j)or[)hyrite,  composed 
of  ])lagioclase,  augite,  and  a  light  brown  biotite,  considerably  altered  to 
chlorite,  apatite  and  magnetite.  It  is  homogeneous  in  texture  and  ap- 
))arently  massive.  Here  and  there  tliis  rock  is  curiously  spotted  witii 
Mesh-colored  chalcedony,  which  occurs  in  it  in  small  kernels  not  dis- 
tinctly amygdaloidal.  The  relation  which  this  rock  may  bear  to  the 
stratified  sediments  of  other  jiarts  of  the  island  remains  uncertain,  as  no 
sedimentary  rocks  were  seen  here.  Basaltic  rocks  are,  however,  ])robably 
abundant  in  the  northern  part  of  the  islaml,  for  fragments  of  such  rocks 
are  common  on  the  beaches. 

The  shores  about  Nikolski  in  some  |)la(>es  show  a  well  marked  low 
terrace,  at  twonty  to  thirty  feet  aV)(>ve  high-water  mark,  which  evidently 
indicates  an  elevation  of  about  that  amount,  as  there  is  a  second  still 
lower  Hat  just  above  the  actual  beach,  which  may  be  accounted  for  by 
tbe  accumulation  of  storm-wash  under  the  present  conditions  or  very 
nearly  so.  This  lower  fiat  is  no  doubt  that  in  which  the  Rhytlna  bones 
were  found  to  be  most  abundant  by  Nordenskjold.  With  these  excep- 
tions no  terracing  was  observed  in  Bering  island.  According  to  Mr  N. 
(irebnitsky,  the  governor  of  the  Commander  islands,  some  fossil  shells 
and  plants  have  been  found  in  the  rocks  of  Bering  island,  which,  f)n 
transmission  by  him  to  Saint  Petersburg,  were  referred  to  the  Miocene 
Tertiary.     Lignite  is  also  found  on  the  island,  but   in  inconsiderable 

XVII— BuLi,.  Gkol.  Sof.  Am.,  Vol.  .'•.,  189:1. 


m'i!Skl',iAiM^f^^'iU','':M 


126 


O.  M.  DAWSOX — COASTS   OF    BERING   SEA    AND    VICINITY. 


;!; 


quantity.  Nordenskjcild  gives  some  general  notes  on  Bering  island,  and 
quotes  a  statement  made  to  liim  by  Mr  Grebnitsky  of  a  character  .similar 
to  the  ahove.^ 

To  the  south  of  Xikolski  the  western  sliore  of  Bering  island  was  not 
seen. 

Copper  Island. — ("opper  or  Medni  island  is  a])out  thirty  miles  in  length, 
with  a  greatest  width  of  nltout  five  miles,  to  the  south  of  the  middle  of 
the  island.  It  forms  a  single  mountainous  ridge,  of  which  the  highest 
})arts  probably  attain  an  elevation  of  ;^,00()  feet,  and  is  much  bolder  in 
t>utline  than  Bering  island.  Its  surface  is  exceedingly  irregular,  and 
comprises  very  little  Hat  land  of  any  kind,  whih;  its  shore  is  often  bor- 
dered by  high  and  rugged  seacliffs,  particularly  along  tlie  southeastern 
side.  The  shoreline  of  this  side  is  sinuous,  while  that  of  the  northeastern 
side  is  deeply  indented  by  several  considerable  l)ays,  butaft'ords  no  good 
harbors  for  large  vessels.  There  are  three  small  settlements  on  the  north- 
east coast — (ilinka,  Karabelny  and  I'reoJjajenski — the  last  named  being 
the  most  northern  and  the  only  one  continuously  oc('Ui)ied  during  the 
winter  months. 

The  island  ajjpears  to  be  almost  entirely  comj)osed  of  volcanic  rocks 
of  some  antiiiuity.  No  volcanic  cones  or  craters  were  ol)serveil,  but,  on 
the  contrary,  the  (existing  relief  is  evidently  the  result  of  oridnary 
denudation.  The  slopes  are  generally  steep  and  are  sometimes  sur- 
mounted by  rocky  crests,  but  are  usually  more  or  less  coni])letelj'  grass- 
covered  from  base  to  sumnut.  The  hills  in  their  form  and  general  appear- 
ance much  resemble  those  of  the  higher  parts  of  Saint  Matthew  island. 

Copper  island  was  crossed  near  its  southeastern  end  from  Glinka 
(Pestchanni  of  sonu;  charts).  At  (Hinka  the  rocks  seem  to  have  a  general 
southeasterly  dip,  and  both  here  and  on  the  other  side  of  the  island  are 
for  the  most  part  gray  and  l)rowni.sh  ])or})hyrites  (augite-porphyrite?), 
with  some  massive  beds  of  coarse  agglomerate.  Where  the  scarped  slopes 
of  the  southwest  side  of  the  island  were  first  reached,  a  bed  ten  to  twenty 
feet  in  thickness  of  a  soft  i)ale  tuflaceous  rock  was  found.  This  consists 
of  small  fragments  and  fine  amorphous  material,  all  apparently  volcanic 
in  origin,  and  contains  embedded  pieces  of  tree-trunks,  sometimes  more 
or  less  silicified,  but  more  usually  in  the  form  of  lignit ).  The  tuff'  was 
observed  in  some  instances  to  fill  what  had  originally  been  hollows  in 
the  rotten  wood.  Below  this  is  a  bed  ten  feet  or  more  in  thickness  of 
coarse  conglomerate  with  well  rounded  stones,  which  also  contains  lig- 
nitized  fragments  of  trees.  The  pebbles  from  the  conglomerate  consist  of 
volcanic  rocks  similar  to  those  common  in  the  vicinity,  and  the  whole  of 
the  water-bedded  intercalation  apjjcared  to  l)e  referable  to  the  temporary 


•  Voyage  of  the  Vesft,  vol.  ii,  pp.  280,  201. 


COPPEU    ISLAND, 


127 


occurrui.fe  of  l)0!U'h  conditions  during  a  stage  of  the  period  of  volcanic 
activity  tc  which  the  rocks  of  the  island  generally  are  due.  The  dij)  at 
this  place  is  southeastward  at  an  average  angle  of  15°. 

In  the  valley  behind  Glinka  village  pretty  definite  evidences  of  terrac- 
ing were  observed  at  several  different  levels.  The  horizontal  lines  are, 
however,  liut  faintly  impressed.  The  highest  of  these  was  estimated  to 
be  600  or  700  feet  above  the  present  aealevel. 

At  Preobajenski,  near  the  northwestern  end  of  the  island,  the  rocks 
seen  were  chiefly  greenish  and  purplish  i)ori)hyritic  materials,  of  which 
no  specimens  were  brought  back.  The  rocks  which  form  a  high  clitT  to 
the  north  of  the  village  at  this  place  were  not  examined.  They  are  well 
stratifie<l  and  dip  in  a  southwestward  direction  at  an  angle  of  about  40°. 
There  is,  however,  nothing  in  their  ai)pearance  to  indicate  that  they  differ 
in  origin  from  the  volcanic  materials  elsewhere  characteristic  of  the 
island.  The  native  copper  from  which  this  island  takes  its  name  is  found 
at  its  northwestern  extremity,  and  specimens  of  it  were  given  to  me  by 
Mr  Tillmann,  the  government  officer  in  charge  of  the  island.  Most  of 
these  are  rounded  nuggets  and  pellets,  wliich  had  evidently  been  picked 
u])  on  the  shore,  but  some  of  them  still  include  fragments  of  volcanic 
rock,  gray  or  reddish,  and  very  probably  an  agglomerate.  A  few  unworn 
pieces  in  the  form  of  sheets  or  more  or  less  dendritic  and  crystalline  frag- 
ments must  have  been  freshly  broken  from  the  containing  rock. 

The  occurrence  of  copper  at  this  place  has  long  been  known,*  and  as 
early  as  1755  the  Russian  government  sent  a  mining  engineer  named 
Jakovlev  to  report  upon  it.f  It  is  believed  that  his  report  was  unfavor- 
able to  the  value  of  the  deposits. 


Kamchatka. 

Favorable  weather  enal)]ed  a  remarkably  good  general  view  to  be  ob- 
tained of  part  of  tlie  Kamehatkan  coast,  in  steaming  along  it  from  the 
latitude  of  Bering  island  to  Avacha  bay.  Its  most  striking  feature  is 
the  series  of  great  volcanic  mountains  which  occur  in  general  parallel- 
ism to  the  axis  of  the  peninsula.  Klotchewsky,  according  to  the  charts, 
is  over  16,000  feet  in  height,  while  Kronotzki,  Japounski  and  Koranski 
attain  10,608,  9,218  and  11,406  feet  respectively.  Several  of  these  moun- 
tains possess  remarkably  symmetrical  conical  forms,  unchanged  by  de- 
nudation and  indicating  continued  growth  and  repair  by  volcanic  forces 
still  near  the  period  of  their  greatest  intensity.  Shishaldin  and  one  or 
two  other  mountains  seen  in  the  Aleutian  islands  show  an  approach  to 


*  Account  of  the  Russian  Dispoverieg  between  Asirt  nn<l  Amcricn,  Coxe,  pp.  123,  206. 
t  Voyage  of  the  VegR,  vol.  ii,  p.  276. 


128 


O.  M.  DAWSON — COASTS   OF    IJKRINd   SKA    AND    VICINITY. 


such  regularly  conical  forms,  but  taken  as  a  whole  the  volcanoes  of  the 
Aleutian  chain,  as  compared  with  those  of  Kamchatka,  are  but  stunted 
and  irregular,  the  general  impression  conveyed  by  such  a  comparison 
being  that  of  the  much  greater  age  and  dwindling  condition  of  vulcanism 
in  the  Aleutian  region^  where  the  jjroccsscs  of  waste  have  for  a  long  time 
outstripped  those  of  accretion. 

Besides  the  donlinant  volcanic  cones,  covered  or  heavily  striped  with 
snow,  there  is  much  irregularly  mountainous  or  hilly  country  of  lower 
elevation.  Very  i)ossibl}'  this  also  may  be  largely  volcanic  in  origin, 
but  if  so  it  has  been  denuded  and  scul[)tured  into  ordinary  systems  of 
hills  and  valleys  like  the  mountains  of  most  of  the  Aleutian  islands 
already  described,  probably  in  later  Tertiary  times. 

There  is  also,  ahjng  this  part  of  the  coast,  evidence  of  a  plane  of  marine 
denudation.  This  plane  was  ol>served  particularly  about  cape  Japounski 
or  Tshipunski,  where  it  gives  form  to  the  end  of  the  promontory,  and 
spreads  along  the  bases  of  the  higher  hills  sometimes  with  a  width  of  a 
mile  or  more.  At  cape  Japounski  (estimating  from  the  heights  given 
on  the  charts)  this  plane  is,  in  its  higher  parts,  7(X)  to  800  feet  above  the 
present  sealevel,  but  declines  gradually  to  its  seaward  edge,  where  it  is 
about  600  feet  in  height.  Traces  of  the  same  or  a  similar  plane,  though 
at  a  somewhat  lower  level,  were  again  seen  in  the  immediate  neighbor- 
hood of  Avacha  ]>ay. 

At  cape  Japounski  this  tiat  bordering  land  or  narrow  plateau  has 
itself  been  since  cut  through  by  narrow  V-^haped  valleys  which  run 
from  the  inland  hilly  tract  to  the  sea.*  The  excavation  of  the  later 
valleys  seems  to  have  occurred  while  the  land  stood  some  fifty  or  one 
hundred  feet  below  its  present  level,  for  the  valleys  are  not  cut  down  to 
the  sea,  but  terminate  seaward  at  such  heights  above  the  waterline.  The 
coast  cliff  may  l)e  re[)resented  diagramatically  thus  : 


("', ' 


FiouHK  .i.— Diagram  illustrating  the  Profile  of  the  Coast  Cliffs  at  Cape  Japounski, 

That  the  plateau  of  cape  Jajiounski  is  not  one  of  deposition,  but  subse- 
quently impressed,  is  shown  by  the  fact  that  the  underlying  rocks  are 
seen  in  the  seacliffs,  particularly  near  the  extremity  of  the  cape,  to  be 
well  stratified  and  to  be  inclined  at  various  angles,  which  are  sometimes 
rather  high  and  are  entirely  independent  of  the  level  contour  of  the 


*  The  general  appenrance  of  cape  Japouuskl  is  very  well  illustrated  in  view  no.  3  on  chart  no,  84,, 
U.  S.  Hydrographio  offloo. 


KAMCHATKA. 


129 


plane  of  denudation.     Tliese  rocks  may  very  proljably  be  similar  to  thoae 
of  Petrapavlovsk,  l)ut  they  were  not  examined. 

Dia<:;ramatically  the  general  structure  of  this  part  of  the  Kamcliatka 
peninsula  may  be  represented  as  atio^i;,  but  it  must  be  understood  that 
the  illustration  is  not  an  actual  drawin<f  of  anj'  one  part  of  the  coast. 
The  order  in  time  of  the  origin  of  its  several  features,  as  indicated  by  the 
form  of  the  land  and  with  reference  merely  to  their  relative  age,  being  as 
follows : 

1.  Stratified  rocks,  upturned,  and  denuded  into  .systems  of  hills. 

2.  Prolonged  depression  of  (500  to  800  feet,  during  which  a  plane  of 
marine  denudation  was  formed,  while  the  sculpture  of  the  inland  hills 
continued. 

3.  Elevation  of  the  land  to  within,  say,  one  hundred  feet  of  its  present 
level,  during  which  narrow  valleys  were  cut  out  across  the  plane  of 
marine  denudation. 

4.  Further  elevation  of  the  land  to  about  the  present  level,  after  which 
wide  delta  flats  have  been  formed,  as,  for  instance,  tliat  in  the  bay  west 
of  cape  Japounski  and  that  about  the  mouth  of  the  Avacha  river. 
These  are  so  well  marked  as  to  indicate  a  considerable  lapse  of  time. 


u 


rnr . 


FiauBK  \.— Diagram  illustrating  the  orographic  Characters  of  the  southern  Part  of  Kamchatka. 

The  towering  volcanic  cones  must,  of  course,  have  been  formed  at  a 
eomi)aratively  late  date  in  this  history,  and  their  growth  has  continued 
up  to  the  present. 

Avacha  bay,  entered  by  a  narrow  strait,  expands  within  to  a  wide  body 
of  water  from  six  to  ten  miles  across.  The  little  harbor  of  Petrapavlovsk 
is  situated  on  the  east  side  of  the  bay. 

The  rocks  met  with  about  this  harbor  are  well  stratified,  often  in  regular 
layers  a  few  inches  only  in  thickness.  Thoy  con.sist  of  gray,  black  and 
greenish  folsites,  hard  argillites,  generally  very  fine  grained,  associated 
with  gray,  blackish  or  greenish  halleflinta  and  greenish  diabase  or  chlo- 
ritic  rocks,  generally  schistose.  All  these  are  much  indurated  and  con- 
siderably disturbed,  sometimes,  for  limited  areas,  actually  contorted. 
They  are  frequently  broken  by  small  faults,  as  well  as  by  innumerable 
joints,  cutting  in  all  directions,  so  as  to  shatter  easily  under  the  hammer 
and  to  form  by  weathering  rubl)ly  slopes.  While  these  rocks  are  evi- 
dently in  part  composed  of  ancient  volcanic  materials,  they  must  have 


t 


mtm 


"91 


I! ''I 


;  I 
.  i 


I   'i 


130 


(i.  M.  DAWhON — COASTS    OV    BERING    SEA    AND    VICINITY. 


been  laid  down  in  water,  and  date  from  a  period  much  more  remote 
than  that  of  the  existing  volcanoes.  They  closely  resemble  in  lithologic 
character  some  of  the  Paleozoic  and  Triassic  rocks  met  with  in  British 
Columbia,  and  in  their  degree  of  alteration  are  like  to  those  already  noted 
as  occurring  on  Attu  island ;  l)ut  as  such  characters  dei)end  chiefly  on 
the  degree  and  nature  of  metamorphism  to  which  the  beds  have  been 
subjected,  they  afford  little  clew  to  the  real  age  of  the  rocks.  No  trace 
of  organic  remains  could  be  found  in  them. 

In  the  vicinity  of  the  harbor  these  rocks  have  preponderantly  southerly 
dips  at  rather  high  angles,  and  a  thickness  of  several  thousand  feet  of 
them  is  here  displayed.  At  the  coaling  place,  near  the  entrance  to  the 
harbor  on  its  west  side,  they  dip  south  10°  east  (magnetic)  at  an  angle 
of  30°,  and  similar  dips  are  found  along  all  this  side  of  the  harbor. 
About  a  mile  outside  the  harbor,  on  the  east  shore  of  Avacha  bay,  similar 
rocks  are  seen  in  low  cliffs,  dipping  south  40°  west  (magnetic)  at  an  angle 
of  60° ;  but  in  following  the  shore  into  the  harbor  varied  and  irregular 
dips  are  met  with.  Fui'ther  out,  beyond  a  deep  indentation  in  Avacha 
bay,  the  stratification  in  some  of  the  cliffs  appears  to  be  nearly  hori- 
zontal. 

Mr  Collie,  in  the  Zoology  of  Captain  Beechey's  Voyage,  notes  the  occur- 
rence of  serpentine  as  a  frequent  constituent  of  the  older  rocks  about 
Avacha  bay.  These  rocks,  as  represented  in  the  immediate  vicinity  of 
Petrapavlovsk,  he  refers  to  in  a  general  manner  as  clay-slates.* 

On  the  east  side  of  the  harbor  of  Petrapavlovsk,  behind  the  village,  a 
distinct,  though  faintly  impressed  line  running  along  the  hill,  seems  to 
indicate  the  existence  of  an  old  sea-margin  at  a  height  of  about  2o0  feet 
above  the  present,  but  apart  from  this  no  evidences  of  terracing  were 
observed  at  this  i)lace.  Neither  were  any  erratics  or  bowlder-clay  met 
with  ;  nor  were  any  striated  rock-surfaces  or  other  evidences  of  glaciation 
anywhere  seen.  So  far  as  they  go,  such  observations  are,  of  course,  en- 
tirely negative  in  character;  but  it  may  be  affirmed  that  no  traces  of  the 
Glacial  period,  such  as  those  so  commonly  found  on  the  coast  of  British 
Columbia  and  that  of  southeastern  Alaska,  are  here  apparent. 

PiuBiLOK  Islands. 


y.: 


Mr.  J.  Stanley-Brown,  of  the  United  States  Geological  Survey,  during 
his  residence  upon  these  islands  in  1891,  made  a  thorough  examination 
and  survey  of  them.  The  main  results  of  his  work  are  given  in  brief 
iu  a  paper  lately  read  before  the  Geological  Society  of  America.f     Mr 


♦ZoSlogy  of  Captain  Beeohey's  Voyage,  London,  1839,  p.  167. 
t  Bull.  Geol.  Soc.  Am.,  vol.  iii,  p.  49fi. 


PRIBILOF    ISLANDS. 


131 


•emote 
lologic 
British 
'  noted 
3rty  on 
e  V»een 

0  trace 

atherly 

1  feet  of 
!  to  the 
11  angle 
harbor. 

,  siinilar 
m  angle 
rregular 
Avacha 
rly  hori- 

le  occur- 
cs  about 
cinity  of 

village,  a 
seems  to 

250  feet 
;ing  were 
clay  met 

aciation 
)urse,  en- 
263  of  the 
^f  British 


y,  during 

in  li  nation 

in  brief 

•ica.t     Mr 


Stanley-Jkown  found  the  islands  to  bo  entirely  volcanic,  and  for  the 
most  i)art  basaltic.  The  centers  of  eruption  are  still  recognizable,  and 
the  date  of  origin  of  the  accumulations  is  regarded  a.s  post-Pliocene.  No 
erratics  are  found  upon  the  higher  levels  and  there  are  no  traces  of  gla- 
ciation  either  general  or  local.  Raised  beaches  were  not  obsferved,  except 
in  one  instance  which  is  believed  to  be  due  to  local  volcanic  disturbance. 
The  island  of  Saint  (ieorge  has  been  consideraly  affected  by  orographic 
movement  since  its  formation,  but  that  of  Saint  I'aul  is  believed  to  have 
remained  unchanged. 

Though  several  visits  were  made  to  these  islands  during  the  summer 
of  1891,  my  opportunities  for  geological  observations  there  were  very 
small  as  compared  with  those  of  Mr  Stanley-Brown  and  the  facts  noted 
therefore  require  the  briefest  mention  only. 

The  most  interesting  locality  on  either  island  is  iindoubtedly  that  of 
Black  bluff.  Saint  Paul  island,  where  fossils  have  been  collected  by 
Wassressenski,  Elliott  anil  others  as  well  as  by  Mr  Stanley-Brown.  1 
had  the  pleasure  of  visiting  this  place  with  the  last  named  gentleman, 
and  entirely  concur  with  his  view  as  to  the  mode  of  occurrence  of  the 
fossils,  namely,  that  they  are  found  only  in  detached  fragments  of  cal- 
careous argillite  which  are  included  in  a  deposit  of  basaltic  scoria  and 
volcanic  ash.*  The  distinctly  bedded  character  of  this  enclosing  rock, 
however,  leads  nxe  to  l)elieve  that  it  was  laid  down  under  water,  the 
products  of  the  volcanic  eruption  being  there  mingled  with  fragments 
ripped  up  from  the  sea-bed  by  the  same  force.  If  this  view  be  correct, 
it  follows  that  the  island,  or  this  part  of  it  at  least,  has  been  elevated  by 
an  amount  of  at  lea.st  80  feet  since  the  time  of  the  eruption. 

The  manner  in  which  the  fossils  occur  at  this  i)lace  shows  that  they 
cannot  be  accei)ted  as  fixing  the  precise  age  of  the  formation,  but  only 
as  representing  some  beds  which  already  existed  at  that  time.  Thus 
the  fact  that  all  the  molluscs  collected  here  l)y  Mr  Stanley-Brown  are 
still  living  species,  while  earlier  collections  included  some  species  now 
extinct,  ])resents  no  difficulty .f  It  tends  merely  to  show  that  deposits 
duo  to  the  upper  Miocene  (Astoria  group  of  Dall ),  with  others  to  which 
a  post-Pliocene  date  must  be  attributed,  occur  in  the  bed  of  this  part 
of  Bering  sea,  and  to  confirm  the  later  post-I'liocene  date  accorded 
to  eruptions  whit'h  have  produced  the  islands. 

Another  fact  which  seems  to  show  that  the  island  of  Saint  Paul  must 
have  been  upraised  to  some  extent  since  the  date  of  the  period  of  vul- 
canisni  is  the  difference  of  contour  which  exists  between  the  higher  hills 
of  the  island  and  the  sometimes  widely  extended  lower  slopes  attaching 

•  Op.  cit.,  p.  497. 

top,  eit.,  p.  498.    Bull.  U.  S.  Geol.  Survey,  uo.  84,  pp.  257,  258. 


132 


Cr.  M.  DAWSON — COASTS   OP    BERING   SKA    AND    VICINITY. 


!l 


!    ! 


l!!:ii 


iiiji 


,t! 


to  them.  Tho  profile  of  the  .soutliern  wide  of  the  iHlaiid  a.s  seen  from 
Nortlieast  point  may  be  sjiecially  iuHtaneed.  Hero,  from  the  steep  slope 
of  Polovina  hill,  a  very  gently  inclined  plain  extends  seaward  to  the 
edge  of  the  low  modern  seacliffs  which  now  border  the  actual  shore. 
This  tlat  tract  is  covered  with  scoriaceous  materials.  Its  highest  part  is 
at  anelevati'-n  of  about  1(X)  feet  above  the  present  sealevel,  and  its  exist- 
ence appeared  to  me  to  be  most  easily  explained  by  supposing  that  the 
volcanic  ejecta  were  here  distributed  and  levelled  as  they  fell  in  a  shal- 
low sea.  An  examination  of  Mr  Stanley-Brown's  contoured  map  of  the 
island  *  will  show  that  (apart  from  seaclitl's)  the  sloi)e8  below  the  1(X)- 
foot  contour  line  are  throughout  notably  light,  while  those  above  it  are 
nearly  all  much  steeper.f 

On  the  low  flat  land  of  the  Northeast  point  of  Saint  Paul  island,  the 
bones  of  whales  and  walrus  are  found  in  considoral)le  al)undance  im- 
bedded in  sandy  deposits.  These  lie  at  a  height  of  some  feet  above  the 
highest  level  of  modern  storm-wash. 

As  it  is  imi)ossible  that  the  remains  of  whales,  at  least,  could  have  been 
carried  to  their  present  position  otherwise  than  by  the  sea  (the  island 
having  been  uninhabited  till  the  time  of  its  discovery  by  the  Russians, 
about  1(X)  years  ago),  it  appears  to  be  certain  that  the  land  has  been 
further  raised  within  ([uite  recent  times  by  an  amount  sufHcient  to 
account  for  their  presence — say,  about  ten  feet.  Evidence  to  the  same 
effect  is  also  found  in  this  vicinity  in  the  wide  flat  to  the  west  of  Plutchin- 
son  hill,  wliere  the  superficial  sandy  deposits  have  at  some  former  time 
been  stripped  away  by  the  sea,  leaving  a  bowlder-strewn  tract  which  is 
bounded  on  the  inland  side  by  a  low  step  or  rise. 

In  his  account  of  the  Pribilof  islands  (page  499)  Mr  Stanley-Brown 
writes  as  follows : 

"There  are  two  fragmentn  of  paleontologic evidence  nonnected  with  thow  is^lands 
which,  aH  they  have  been  used  by  writers,  demand  a  cautionary  word.  The  tuHk 
of  a  mammoth  waa  found  in  tlie  wands  of  Nortlieast  j.oint  on  Saint  Paul  iMland,  and 
the  tooth  of  one  is  reported  as  cominj;  from  tiie  shores  of  Saint  George.  As  there 
is  not  a  foot  of  earth  upon  either  island,  save  that  which  has  resulted  from  the 
decomposition  of  the  native  rock  and  the  decay  of  the  vegetation,  the  value  of  such 
testimony  is  (juestionable." 

Dall  attributes  more  importance  to  these  discoveries,  and  authenticates 
that  on  Saint  George  on  the  evidence  of  Veniaminof,J  while  he  also 
quotes  Stein  as  an  authority  for  the  occurrence  of  similar  remains  on 


*  Fur-8eal  Arbitration  :  Case  of  tlie  United  States,  map  no.  2. 

tit  is,  liowever,  to  be  remembered  that  Mr  Stanley-Brown's  examination  of  tlie  island  led  him 
to  refer  the  differences  here  commented  on  to  other  causes,  which  may  possibly  afford  a  sufficient 
explanation  of  them. 

I  Op.  cit.,  p.  2UG, 


KlJXtVAK     ISLAM). 


133 


from 
slope 
:>  the 
Hiore. 
jiirt  is 
exist- 
at  the 
I  Hhal- 
of  the 
le  1()0- 
!  it  are 

ud.  the 
ice  im- 
ove  the 

ve  been 
3  island 
ussians, 
as  been 
cient  to 
he  same 
lutchin- 
nei-  time 
which  is 

-Brown 

»Ho  islands 

The  tvwk 

4and, and 

Ak  there 

from  the 

me  of  pueh 

icnticates 
he  also 
mains  on 


ilmid  led  liim 
•d  ft  sufficient 


I'liahiska  island.  It  will  bo  ol)servod  that  Mr  Stanlo^'-Hrown  does  r')t 
question  the  fiiidinjf  of  the  mammoth  remains  on  the  I'ribilof  islands, 
and  I  do  not  attach  the  same  significance  to  the  absence  of  extraneous 
earthy  matter  in  the  soil  to  which  he  refers.  This,  in  fact,  appears  to 
afford  fnrther  reason  to  believe  that  the  bones  could  not  have  been  carried 
thither  in  any  adventitious  manner,  and  to  render  it  as  nearly  as  ])os- 
aible  certain  that  the  animals  to  which  they  belonged  must  have  found 
their  way  to  the  islands  at  a  time  when  they  were,  connected  with  the 
American  continent  by  means  of  a  wide  plain,  such  as  Mr  Stanley-Brown 
himself  exjdains  in  one  of  the  i)aragrai)hs  of  his  paj)er,t  would  be  made 
if  an  elevation  of  200  feet  should  now  take  place  in  Bering  sea. 

The  absence  of  old  sea-margins  on  the  I*ril)ilof  islands  may  be  accepted 
as  showing  that  since  the  time  of  their  original  elevation  above  the  sea 
they  have  not  been  again  submerged,  but  there  is  no  evidence  whatever 
to  show  that  they  may  not  have  stood  at  higher  levels. 

My  observations  agree  with  those  of  Mr  Stanley-Brown  in  regard  to 
the  abs'cnce  of  erratics  above  the  present  sea-margin,  but  it  may  be  added 
that  not  infrecpient  pebbles  and  small  bowlders  of  granitic  rocks  occur 
upon  the  actual  beaches  in  association  with  local  debris.  These  have 
in  all  probability  been  brought  hither  either  by  the  Hoe-ice,  which  fills 
this  part  of  Bering  sea  in  winter,  or  attached  to  the  roots  of  drift  tree- 
trunks,  which  are  often  washed  ashore. 

NuNiVAK  Island. 

The  form  of  Nunivak  island  is  very  imperfectly  represented  on  the 
charts.  It  was  apj)roached  by  us  on  the  7th  of  August  on  its  south- 
western side,  where  a  landing  was  effected.  On  the  following  daj'  the 
western  and  northern  shores  were  coasted  at  a  distance  as  small  as  ap- 
peared to  be  compatible  with  safety,  and  the  next  night  was  spent  at 
anchor  in  Eteolin  harbor,  at  the  northeastern  extremity  of  the  island. 

The  island  is  throughout  grass-covered,  but  entirely  devoid  of  trees, 
though  a  few  stunted  shrubs  are  found  in  some  of  the  valleys.  Its 
coasts  are  usually  rather  low,  but  vertical  cliffs  of  100  to  150  feet  in 
height  appear  at  the  points  and  projecting  headlands,  while  shelving 
rocky  shores,  with  occasional  sandbeaches  and  sanddunes,  characterize 
the  various  open  bays.  Tlie  cliffs  show  several  superposed  and  horizon- 
tal layers  of  basaltic  rock,  and  in  the  low  hills  of  the  interior  of  the 
island  similar  but  overlying  massive  flows  of  the  same  kind  may  be 
traced.  These  hills  are  all  more  or  less  plateau-like  in  form,  and  might 
readily  be  mistaken  in  some  places  for  old  marine  terraces.     The  highest 

♦Op.  cit.,  p.  49«. 
XVIII— Bull.  Geoi..  Soc.  Am.,  Vol.  r>,  1893. 


/ 


134 


a.  M.  DAWSON — COASTS   OV    BERINO   SKA    AND    VICINITV. 


':'  I 


ii! 


parts  ol'tlu'  isliind  were  OMtiniatcd  at  about  50()  tW't.  At  F'^toolin  liarl)()r 
tho  rock  is  aj^ray  oliviiio-dialiase,  vory  jjohjus  and  ocillular,  and  neparatcd 
into  layers  which  siniilate  liorizontal  heddinjr,  hut  which  are  due  to  How 
Htrncture. 

I'art  of  the  eant  coast  of  the  island  was  suhse(|nently  seen  from  a  dis- 
tance, and  its  ap[)earance  is  so  similar  to  tliat  of  tiie  otlu!r  coasts  tl)at 
there  can  be  little  doubt  that  the  island  is  entirely  composed  of  nearly 
horizontal  basaltic  Hows.  Tiie  basalts  examincid  are  all  fresh  lookinjf 
and  unaltered,  like  those  of  Saint  Paul  island.  'Die  much  altered  sand- 
stones reiH)rted  by  Dall  at  Eteolin  harbor  were  not  found,  nor  was  I  able 
to  identify  any  volcanic  cones  upon  this  island.* 

No  erratics  or  traces  of  glaciation  were  observcnl  on  tho  parts  of  Nuni- 
vak  island  visited. 

Cape  Vancouver. 

Cape  Vancouver,  twenty-five  miles  distant  from  the  eastern  coast  of 
Nunivak  island,  is  a  projecting  point  of  Nelson  island,  Avhich  is  to  all 
intents  a  portion  of  the  adjacent  Alaskan  mainland.  It  is  a  bold  and 
high  promontory,  which,  thougli  scarcely  to  be  characterized  as  moun- 
tainous, rises  to  a  height  of  probably  1,000  or  IpOO  feet.  It  evidentl}' 
forms  one  of  several  or  many  projections  of  higher  land  along  this  part 
of  the  .\laskan  coast,  which  are  connected  by  broad,  low,  level  tracts. 
The  north  shore  of  the  cape,  which  alone  was  examined,  forms  scarped 
blutfs  or  clitl's,  rising  from  the  edge  of  the  sea,  and  presenting  fine  ex- 
])()sures  of  sandstones  and  sandy  shales,  well  bedded  and  dipping  south- 
ward, at  low  and  undulating  angles.  At  the  extremity  of  tlii^  capejthe.se 
beds  ai)i)eared  to  be  horizontal,  and  on  the  south  side,  though  imper- 
fectly seen  from  a  distance,  they  seem  to  lie  at  higher  and  more  irregular 
inclinations. 

The  sandstones,  where  examined,  are  grav,  bluish  and  brownish  in 
(H>lor,  rather  soft,  and  sometimes  nodular.  They  contain  a  few  very  thin 
and  dirty  seams  of  coal  or  lignite,  of  which  the  thickest  seen  was  only 
a  few  inches.  There  are  also  in  the  sandstones  numerous  carbonace<)ns 
fragments  and  occasional  fossil  leaves,  of  which  a  couple  were  collected. 
These  have  been  submitted  to  Sir  J.  \\'illiam  Dawson,  who  sup])lies  the 
following  note  upon  them  ; 

"No.  I.  Jiiglnns  (irinninatti,  K.  Briiun,  Heor,  Flora  Fo.^Hilis  Alaskana,  ISOO,  page 
38.  Ih.,  Flora  Fns.silis  Arctica,  vol.  I.  Ih.,  Contributions  to  Fossil  Flora  of  N. 
(ireenland.     Trans.  Koyal  Society,  18(59. 

"  This  species  is  stated  by  Ileer  to  occur  in  sandstone  at  En^lisb  bay,  Alaska.  It 
is  also  found  at  Atanekerdluk  in  Greenland,  and  is  said  to  occur  in  the  European 


»Cf.  Dnll,  op.  cit.,  p.  245. 


CAPE    VANCOUVKU. 


135 


larlit)!" 
!irut(Ml 
()  How 

1  a  tlis- 
,rt  that 
nearly 
ookinji; 
I Hand- 
!  I  able 

[■  Nuni- 


coast  of 
is  to  all 
)ol(l  and 
s  nioun- 
vidently 
tluH  part 
L'l  tracts. 
!  scarped 
r  fine  ex- 
1!^  south- 
vpclthese 
1  iniper- 
in-o>fular 

wnish  in 
very  thin 
was  only 
)onacc'()US 
collected. 
)l)lioH  the 

1H()0,  page 
'loi-a  of  N. 

Alaska.     It 
r,uroi)oau 


MicK'oiio  at  Oeninnfen  and  Hohc  Blimen.  Very  Hiinilar  HpccicH,  if  not  mere  varietal 
foriUH,  an-  cipditcd  by  I-cwiiii'iiMix  and  Ward  to  tlie  Laramie  and  Tertiary  of 
western  Anu'ricu.  Tlie  plaiitn  found  witii  tliiw  Hi)ei'ieH  at  Kngiiwli  Imy,  Alawiva,  and 
at  Alanekerdluk,  Ureenland,  are  ohwely  allied  to  those  of  the  upi)er  Laramie  of 
Canada,  and  I  have  been  inclined  to  refer  tlieni  to  tins  ago  rather  than  to  the 
Miocene. 

"  No.  '2.  Fra>;ment  of  a  leaf  of  considerable  size,  but  too  inii)erfect  for  determina- 
tion. It  may  possibly  have  belonged  to  a  species  of  (^lurcun  or  of  a  large  CoryliiH, 
like  ('.  Mriinaini,  but  this  is  (juite  uncertain." 

Accordinjj  to  the  claHHification  adopted  l)y  J)r  Dall  in  his  recent  work, 
the  beds  at  ea])e  Vancouver  would  appear  to  fall  under  the  Kenai  {;ruui> 
of  the  Miocene,  though  the  locality  is  a  new  one.* 

Upon  the  heach  at  cape  Vancouver  fragments  of  vesicular  hasalt  are 
al)undant,  and  the  distant  outline  of  the  cape  led  me  to  suppose  that  the 
stratified  rocks  are  capped  by  basaltic  Hows  in  the  higher  hills  a  short 
distance  inland  from  the  extremity  of  the  cape. 

A  fairly  distinct  though  rather  narrow  terrace  of  earthy  materials  was 
observed  along  the  north  shore  of  the  cape  at  a  height  of  8U  to  100  feet 
above  the  sea. 

Saint  Matthkw,  Hall  and  Pinnacle  Islands. 

Saint  Alatthew  island,  with  Hall  and  Pinnacle  islands  near  it,  are 
situated  in  the  center  of  the  northern  part  of  Bering  sea.  They  are  so 
remote  from  any  other  land  that  they  ajjpear  never  tt)  have  been  reached 
by  the  Eskimo,  though  polar  bears  are  brought  to  them  on  the  floe-ice  of 
winter  and  remain  during  the  summer.  Saint  Matthew  island  itself  is 
long  and  narrow,  extending  in  a  northwest  by  southeast  direction  for 
about  thirty  miles.  Hall  island,  some  five  miles  in  greatest  length,  lies 
near  the  northwest  end  of  Saint  Matthew,  and  Pinnacle  island  is  situated 
at  a  distance  of  six  or  seven  miles  to  the  south  of  the  main  islands.  The 
islands  are  very  imperfectly  delineated  on  the  existing  charts. 

Saint  Matthew  island  may  bo  described  as  consisting  of  the  unsub- 
merged  portion  of  a  range  of  bold  rounded  hills,  some  parts  of  which 
probably  reach  an  elevation  of  about  1,500  feet.  It  is  in  reality  formed 
of  three  isolated  groups  of  hills  of  unecpial  size  which  may  originally  have 
been  separated  by  narrow  straits,  but  are  now  united  by  tracts  of  low 
gravelly  land  washed  \x\)  by  the  action  of  the  sea.  These  low  lands  in- 
clude several  lagoons,  into  \vliieh  streams  fall  and  from  which  the  water 
percolates  through  the  gravel  to  the  sea.  Hall  island  is  in  every  way 
similar  to  Saint  Matthew,  but  happens  to  be  divided  from  it  by  a  still 
existing  strait. 


*  Op.  cU.,  p.  234. 


'f  fru-t  <ve 


1  '* ' 


ISB         O.  M.  DAWSON — (OASTS   oK    l»KHIN(»    SEA    AND    VICINITY. 

The  forniH  of  the  hills  aro  not  ruj;^to(l  or  Hcarpod,  hut  they  have  been 
cut  hack  into  scaclilTs  of  varyinj^  hci^'ht  ahiiij;  all  tho  nhorcs. 

There  is  no  appearance  of  volcanic  craters,  cones  or  centorH  of  eruption, 
nor  \v(!rc  any4.volcanic  rocks  of  surface  orijfin,  such  as  the  l)aHalts  of  tlio 
I'rihilof  and  Nunivak  islands,  seen  aliout  those  island.^'.  The  hills  neeni 
to  he  the  residual  portions  of  much  more  extensive  volcanic  accumula- 
tions of  some  anti(|uity,  of  which  the  j;reater  part  has  heen  removed  hy 
ordinary  jirocesscs  of  denudation.  So  far  as  examined,  they  were  found 
to  he  com])ose(l  of  rocks  j^enerally  less  hasic  in  composition  than  the 
hasalts  and  prohahly  in  the  main  of  deep  seated  origin,  hut  neverthe- 
less entirely  volcanic  or  eru[)tive.  No  raised  heaches  or  terraces  were 
ohserved,  nor  went  any  rcco^^ni/.ahle  instances  of  travelled  bowlders  or 
traces  of  {glaciated  rock  surfaces  seen  on  the  islands  of  this  group. 

The  following  more  detailed  notes  include  the  results  of  examinations 
made  on  August  10,  11  and  12,  1891: 

The  cliil's  at  cape  I'pright,  the  eastern  end  of  Saint  Matthew  island, 
are  in  some  places  about  500  feet  in  height,  very  rugged  in  forni  and 
tenanted  by  numerous  seabirds.  The  sea  has  here  cut  back  beyond  the 
crests  of  a  small  group  of  liills,  so  that  the  ground  slopes  away  steejdy 
inland  from  the  summit  of  the  clitt's.  The  rocks  arc  everywhere  very 
much  shattered  and  jointed.  They  consist  of  greenish  and  purplish 
feldspatliic  materials,  often  porphyritic,  in  many  cases  evidently  cla.stic, 
and  in  one  i)lace  including  a  hard,  ])ale  greenish  tutt".  These  are  asso- 
ciated with  a  gray  fragmental  rock  chiefly  composed  of  granitic  material, 
with  Tunch  ejjidote  and  chlorite.  This  simulates  a  granite,  but  contains 
also  angular  fragments  of  the  darker  j)orphyrites.  Nearly  all  these  rocks 
are  considerably  docomp(>sed,  and  resend)le  rocks  met  with  in  British 
Columbia,  where  the  centers  of  eruption  of  Miocene  date  have  been  cut 
through  or  exposed  by  denudation. 

Tn  following  the  north  coast  of  Saint  Matthew  island  from  cape  Upright 
to  its  deepest  indentation,  which  forms  an  open  bay,  where  we  anchored, 
a  stretch  of  low  land  with  gravel  beach  is  first  i)assed.  Cliffs  then  border 
th-^  S.P'  a'Td  are  composed  of  rather  massive  rocks  of  dark  color,  resem- 
bling those  above  described.  In  rounding  the  most  prominent  point 
between  cape  Upright  and  the  bay,  however,  a  thick  stratum  of  a  grayish 
yellow  color  is  ol)served  in  the  elif!'.  This  rests  with  perfect  regularity 
on  the  darker  rocks  below,  but  its  upper  surface  appears  to)have  been 
plowed  up  by  the  passage  over  it  of  tho  overlying  material  in  a  molten 
state.  The  general  dip  of  the  beds  is  southward  at  an  angle  of  about  15°. 
The  light  colored  material  is  probably  tufi'or  fine  volcanic  agglomerate. 

From  the  anchorage  westward,  the  rocks  of  the  north  shore  of  Saint 
Matthew  island  were  seen  only  from  the  sea.     They  appeared  to  be 


i-*    '4 


II 


.1 


SAINT    MATTHKW,    HALL    AND    FINNA<"LK    ISLANDS. 


137 


been 

)ti<)n, 
»f  tho 
Hecni 
mula- 

ed  l)y 
found 
,n  the 
erthe- 
8  were 
era  or 

uitions 

island, 
m  and 
)ud  the 
steeidy 
ire  very 
lurplish 

clastic, 
re  aaso- 

atcrial, 

iitains 

sc  rocks 

iritish 

)een  cut 

pright 
ichored, 
l)order 
rt'scni- 
iit  point 
grayish 
(gularity 
ive  been 
molten 
)OUt  15°. 
onieratc. 
of  Sahit 
id  to  be 


Hinular  to  tlume  last  dcHcribt'd,  and  arc  very  prol»ably  of  alxmt  the  Haine 
horizon  throughout.  The  pale  colored  stratuni  referred  to  reappears  at 
several  places,  and  always  witii  a  low  southerly  dip  away  from  the  sea. 

The  soutii  side  of  Saint  Mattlunv  island  was  clearly  seen  from  the  sea 
and  closely  examined  through  tiie  telesco|io  westward  to  al)out  abreast 
of  Pinnacle  island.  Its  general  featunss  and  the  appearance  of  its  rocks 
are  in  every  way  similar  to  those  of  the  north  side. 

The  general  structure  of  Hall  island,  in  whi(!h  the  same  rocks  are  con- 
tinued, is  illustrated  ity  the  subjoined  diagram,  skct(^hed  along  it«  east 
coast. 

The  principal  dij)  is  here  to  the  northward  at  low  angles,  and  the  rocks 
c<»nsist  of  a  series  of  "  porphyrites,"  with  int(!rcalat,ed  tulVaceous  and 
agglonieritic  beds.  The  rocks  shown  at  a,  d  and  /  in  the  diagram,  con- 
sist preponderantly  of  grayish  purple,  purple  and  gray  porphyrites, 
nearly  massive,  but  sometimes  with  a  rude,  irregular,  columnar  structure, 
particularly  toward  the  north  end  of  the  ishmd,  where  the  ro(!k  is  dis- 
tinctly an  augite-porj)hyrite.     Tliey  have  liecn  considerably  altered  and 


FiuuHE  o. — Diagramatie  Section  alonij  the  east  Coast  of  Hall  Island. 

decomposed,  freciucntly  largely  silicified  by  subsequent  solfataric  ac  ion, 
while  they  are  often  markedly  rusty  in  irregular  bands.  C  and  c  are 
pale  gray  in  color,  and  consist  of  tutt",  volcanic  ash  or  fine  agglomerate, 
which  is  evidently  water-bedded,  and  in  some  places  rather  finely  strati- 
fied. Tliis  is  i)articularly  the  case  in  respect  to  the  bed  c,  which  is  from 
2(X)  to  300  feet  tliick,  and  is  underlain  by  a  similar  thickness  (b)  of  coarse 
brownish  and  blackish  agglomerate,  holding  some  fragments  from  one  to 
three  yards  in  diameter. 

The  section  evidently  represents  the  results  of  volcanic  action  which 
has  lieen  in  part  or  altogetln.'r  sul»mariue.  The  rocks  are  everywhere 
much  fractured  and  jointed,  giving  rise  under  the  action  of  the  sea  t<i 
l)ol(l,  rugged  and  picturesque  cliffs  like  those  of  cape  Upright.  Much 
ehalcedon}'  and  jasper  occur  on  the  east  side  of  Hall  island  near  its 
southern  end  in  the  porphyritic  rocks,  and  these  minerals  here  comjjose 
a  considerable  portion  of  the  worn  beach  pebbles  iix  some  places.  The 
chalcedou}'  is  generally  white  or  milky,  the  jasper  red  or  red  veined 
with  yellow. 

In  1791  Sauer,  of  Billing's  Russian  Scientific  Expedition,  landed  on 


^    , 


,    !- 


Iv  ' 


W' 


138 


(i.  M.  DAWSON — COASTS   OF    BEKlNCi    SEA    AND    VICINITY. 


this  island,  probably  near  this  ])lace,  and  particularly  notes  the  a])un- 
dance  of  jasper  and  chalcedony* 

Pinnacle  island  was  so  named  by  Cook  in  1778.  It  is  a  narrow  crest 
of  jagged  rocks,  a])parently  about  a  mile  in  length  and  lying  north  and 
south.  On  some  charts  its  height  is  given  at  900  feet,  and  its  higher 
parts  may  reach  this  elevation,  but  as  its  form  is  very  imperfectly  shown 
on  the  charts  no  accuracy  can  be  attached  to  the  height  stated.  It  pre- 
sents a  series  of  vertical  and  sometimes  overhanging  cliffs  to  the  sea  on 
both  sides,  gashed  by  transverse  breaks  into  a  series  of  narrow  peaks  and 
])innacles.  In  many  places  the  sea  washes  the  base  of  sheer  cliffs  which 
often  show  low  caves  along  the  water  line.  Elsewhere  rough  naVrow 
beaches  permit  a  landing  to  be  made  in  calm  weather. 

Myriads  of  birds  find  nesting  places  in  the  clifli's.  Several  ])olar  bears 
were  also  observed  on  the  island,  and  on  a  low  neighboring  rock  to  the 
southeast  a  considerable  colony  of  sealions  was  noticed. 

Some  hours  were  spent  al)Out  the  island  under  favorable  circumstances 
of  weather  on  August  12,  and  the  shore  was  closely  followed  all  round 
in  the  steam  launch  of  H.  M.  S.  Pheasant. 

The  rocks  are  everywhere  very  similar  to  those  of  cape  Upright,  and 
evidently  belong  throughout  to  the  same  old  volcanic  series.f  Like 
these,  they  are  very  much  shattered  and  disturbed.  Dark  purplish  and 
greenish  feldspathic  rocks,  which  are  often  distinctly  stratified  or  strati- 
form and  dip  at  various  angles,  are  jicrhaps  the  most  abundant.  Some 
beds  of  gray  arkose  material,  like  that  of  cape  Upright,  were  also  seen 
here.  These  are  now  consolidated  into  a  hard  rock,  but  occasionally 
show  very  distinct  stratification.  The  granitic  debris  is  here  embedded 
in  a  chloritic  matrix. 

Saint  Lawrence  Island. 

Saint  Lawrence  island,  the  largest  in  Bering  sea,  is  about  (So  miles  in 
length,  and  is  situated  not  far  to  the  south  of  BT3ring  strait.  The  western 
end  of  this  island  was  coasted  from  Southwest  point  to  cape  Chibukak. 
Between  Southwest  point  and  cape  Sanachno  the  shore  is  formed  by 
rugged  cliffs  several  hundred  feet  in  height,  witli  some  outlying  rocks 
and  reefs.  These  cliffs  are  composed  for  the  most  part  of  a  gray  rook, 
which  from  its  massive  appearance,  as  well  as  from  *he  observations  sub- 
sequently made  at  cape  Chibukak,  is  almost  certainly  granitic.  This  is 
seen  to  be  overlain,  where  higher  ground  approaches  the  shores,  l)y  hori- 

♦  An  Account  of  a  Geogruphicnl  and  Astronomioftl  Expedition  to  the  nortlieru  Parts  of  Russia. 
London,  18o:'  p.  2:15. 

t  The  statement  tlint  Pinnacle  isliunl  js  a  "  volcanic  chimney,  still  smoking"  is  incorrect.  Bull. 
U.  S.  Geo!.  Survey,  no.  84,  p.  258. 


SAINT   LAWRENCE    ISLAND. 


139 


zontal  or  very  li<^htly  inclined  stratified  materials  of  l)ro\vnish  and  red- 
dish brown  colors,  wliich  are  with  little  doubt  volcanic,  but  more  probably 
scoriaceous  or  agglomeritic  than  basaltic.  Low  plateau-like  hills  some 
miles  further  inland  appear  to  be  composed  of  similar  materials.  Higher 
hills,  at  a  greater  distance  from  this  part  of  the  sliore,  were  seen  only 
very  imperfectly,  between  clouds. 

The  northeast  point  of  the  island,  ending  in  cape  ('hibukak,  consists 
of  a  plateau  about  200  feet  in  height,  -with  a  notal)ly  level  outline  as 
seen  from  the  sea.  This  plateau,  however,  declines  to  the  southward  to 
lower  land,  by  which  it  is  connected  with  the  rest  of  the  island.    It  breaks 


seen 

tnally 

dded 


lies  in 
estern 
lukak. 
ned  by 
rocks 
V  rock, 
sub- 
tiis  is 
)V  hori- 


•* 

■  -IJt 

.>^^:^^c^-*...^.- 

'•'^:\:v  •: 

*  '^^^^^^^^^^^^^^^^^^^^^^^^H 

— ■ *- — — •t^ — "t^ 

■'  V-W*. 

'        ,.            „    -t^^V ^   -    _J 

Vui\j\\v.r\— Shattered  granitic  Rocks,  Cape  Chihukak,  Saint  Lawrence  Ixlnnii. 

off  to  seaward  in  clitTs  or  steep  rocky  slopes,  with  here  and  there  pro- 
jecting pinnacles  of  fissured  rock  rising  from  them. 

A  landing  was  made  on  the  east  side  of  cai)e  Chihukak,  where  the 
plateau  was  found  to  consist  of  gray  biotitc-granite  of  uniform  color  and 
texture  and  moderately  coarse  grain.  The  surface  of  the  plateau  is 
everywhere  covered  with  irregular,  angular,  broken  blocks  of  granite, 
much  like  those  often  found  on  high  mountain  summits,  and  doulitless 
the  result  of  severe  climatic  conditions  acting  upon  the  naturally  jointed 
rocks.  No  erratics  were  found  upon  the  plateau  nor  any  traces  of  glacial 
striation  or  smoothing,  though  if  such  at  any  time  existed  they  may 


r 


140 


O.  M.  DAWSON' — OOAHTS   OF    BERING    SKA    AND    VICTNITY. 


i 


m-' 


have  been  lost  in  consequence  of  the  breaking  up  of  the  original  rocky 
surface.  The  impression  conveyed  was,  however,  that  this  condition  of 
the  surface  was  of  ancient  date  and  had  been  i)reserved  because  of  the 
exenii)tion  of  the  region  from  the  eftect  of  glaciating  agents.  Some  stones 
were  found  on  the  i)rosent  beach  which  did  nt)t  appear  to  belong  to  the 
actual  vicinity,  but  if  transported  from  any  distance  the  aliundance  of 
floe-ice  known  to  occur  in  these  seas  in  winter  is  quite  sufficient  to  ac- 
count for  this.  Nothing  whatever  was  found  to  favor  the  theory  of  an 
"  oversweeping  glacier,"  the  sui)posed  action  of  which  has  been  particu- 
larly illustrated  by  Mr  John  Muir  from  the  contours  of  hills  and  cliffs 
on  this  island.* 

The  level  contour  of  the  plateau  suggests  that  it  may  represent  an 
ancient  plane  of  marine  denudation  or  peneplain.  On  tlie  east  side  of 
the  cape  a  fairly  distinct  terrace  occurs  at  a  height  of  about  fifty  feet 
above  the  sea.  This  has  been  out  back  in  the  granitic  rocks  as  a  narrow 
step,  which  is  now  encumbered  with  broken  blocks  from  the  old  sea- 
clift'  above. 

Pla:f«cni 


Terrace  corered 
vntlifall^ii.  rt>f/cAS. 


.-..^fe^ 


Sea  J^evfl. 

FiuuBK  l.~Diagramatic  Section  of  the  east  Side  of  Cape  Chibukak,  Saint  Lawrr.nce  Island. 

VieMS  of  the  island  as  a  whole,  from  cape  Chibukuk,  and  also  from 
the  sea  to  the  westward  with  a  remarkably  clear  atmos])here,  failed  to 
disclose  any  distinct  volcanic  cones  or  craters,  but  as  both  C'aptain 
Hooper  and  Rfr  Muir  speak  very  positively  of  the  existence  of  such 
cones  on  the  island,  it  is  probable  that  they  are  to  be  found  in  its  cen- 
tral or  eastern  parts.f 

The  surface  of  the  island,  so  far  as  seen,  consists  wholly  of  barren 
moorland,  with  grass  and  moss  and  often  rock.  There  are  no  trees,  and 
large  masses  of  snow  were  found  in  some  places  along  the  bases  of  th,e 
clifi,s  and  down  to  the  level  of  the  sea. 

Plover  Bay. 

From  Saint  Lawrence  island  we  crossed  to  the  Siberian  coast  at  Plover 
bay,  80  named  because  H.  M.  S.  Plover,  Captain  Moore,  wintered  there 


•  Report  of  the  cruise  of  the  Corwin,  1881,  pp.  137-140. 
t  Ibid.,  pp.  3a,  140. 


PLOVKR    BAY. 


141 


'lover 
there 


in  1848-'49,  in  connection  with  the  F'ranlclin  seiirch.  It  is  situated  in 
latitude  64°  'HY,  and  indents  the  southern  ])art  of  the  promontory  sepa- 
rating Anadir  hay  from  Bering  strait.  The  weather  was  such  as  to  give 
us  while  approaching  it  a  good  view  of  a  long  stretch  of  this  part  of  the 
Siherian  coast.  The  outlines  of  this  coast  are  everywhere  hold  and 
mountainous,  though  none  of  the  highest  points  in  sight  probahly  ex- 
ceed 4,000  feet  in  elevation.  It  is  entirely  hare  and  treeless,  brownish 
or  gray,  showing  only  here  and  there  in  the  valleys  the  green  color  of 
heritage. 

Fiord-like  inlets,  and  narrow  straits  of  the  same  nature,  characterize 
this  part  of  the  coast,  but  they  are  on  a  small  scale  as  compared  with 
those  of  British  (,'olumbia  and  southeastern  Alaska.  Soundings  given 
on  the  charts  show  that  the  water  in  these  inlets  and  channels  is  deeper 
than  that  about  their  mouths,  but  the  greatest  depth  actually  recorded 
appears  to  be  about  50  fathoms.* 

Plover  bay  is  one  of  these  small  Hords,  surrounded  by  steep,  rocky 
mountains,  notably  covered  everywhere  on  their  slopes  with  talus  ma- 
terial, consisting  of  broken  angular  rock,  through  which  s{)ires  and  crags 
of  solid  rock  often  project,  especially  on  the  sides  facing  the  sea.  Gen- 
erally speaking,  the  mountains  show  ordinary  denudation  forms,  with 
wide  buttress-like  projections  and  intervening  stee|)  valleys  and  ravines  ; 
the  shapes  assumed  resembling  those  commonly  met  with  where  the 
rocks  are  so  much  shattered  and  jointed  as  to  crumble  away  under  the 
weather  with  almost  eipial  facility  in  any  direction.  The  ranges  end 
along  the  coast  in  capes  terminated  by  seacliffs.  On  the  whole,  the 
most  pecidiar  feature  is  the  great  abundance  of  loose  angular  material. 
It  is  doubtful  to  what  extent  this  may  be  directly  referred  to  rapid  dis- 
integration due  to  the  subarctic  climate  of  the  climate,  or  in  how  far  it 
may  be  accepted  as  evidence  of  prolonged  weathering  uninterrupted  ]\y 
glaciating  agents. 

From  cape  Tchalpin  (Indian  point)  to  cape  Nismenni,  and  thence  as 
far  as  cape  Tchukotski,  the  rocks  as  seen  from  the  sea  are  generally  gray 
in  color  and  are  in  all  i)robability  granitic.  Between  the  range  ending 
seaward  at  cape  Tchukotski  and  the  valley  containing  lake  IMooreof  the 
chart  is  a  smaller  range  composed  near  the  sea  of  similar  gray  rocks,  but 
about  two  miles  inland  assuming  brownish  and  reddish  (>olors.  Brownish 
and  reddish  weathering  rocks  also  compose  most  of  the  next  rangt>, 
which  separates  lake  Moore  from  Plover  bay  and  includes  mount 
Slavianka.  From  what  was  afterward  seen  in  Plover  l)ay,  this  differ- 
ence of  coloration  mav  not  indicate  anv  essential  change  incomiiosition. 


*  Dull,  howevor,  siii'iiliH  of  ii  (li'ptli  of  over  KKi  fathoms  liiivinjt  lipeii  o))taInecl  in  thf  oenter  of 
Plover  bny.    AInsUa  luul  Its  Rosoiirprs,  pp.  4r).'>,  nia. 

XIX— Biii.1.,  Okoi..  Soc.  .\ji.,  Vol..  r.,  18!);l. 


142 


G.  M.  DAWSON — COASTS   OF    BERING   SEA   AND    VICIMTV. 


Jiuld  Head,  which  forms  the  seaward  end  of  the  ranj^e  last  referred  to, 
shows  in  its  cliffs  several  well  marked  intrusive  dikes,  weathering  yel- 
lowish and  blackish. 

The  whole  west  side  of  Plover  bay,  as  well  as  the  outer  coast  beyond 
it  for  several  miles,  consists  of  gray  rocks  which  are  likewise  probably 
granitic. 

The  only  locality  in  which  the  rocks  were  actually  examined  in  this 
region,  in  the  short  time  available,  was  the  east  side  of  Plover  bay  between 
port  Providence  and  Ennna  harbor.  They  are  here,  in  the  main,  rather 
coarse  grained,  gray  biotite-granite,  much  like  that  of  the  west  end  of 
Saint  Lawrence  island,  l)Ut  in  places  passing  into  a  horn])lendic  granite. 
There  is  also,  however,  a  considerable  proi)ortion  of  gray  and  reddish 
porphyritic  rock,  resembling  a  mica-syenite  or  minette,  which  is  prob- 
ably later  in  date  than  the  granite  and  intrusive  iiv  it.  No  strictly 
volcanic  rocks  of  any  kind  were  seen  in  this  vicinity,  nor  were  any  strati- 
fied rocks  observed. 

The  general  description  of  this  part  of  the  Siberian  coast  above  given 
will  show  that  superficial  earthy  deposits  are  not  abundant,  but  there 
are  in  the  vicinity  of  Plover  bay  some  deposits  of  this  kind  Avhich 
attracted  special  attention. 

The  point  on  the  outer  coast  immediately  east  of  the  valley  of  lake 
Moore,  terminates  in  an  apron-like  flat  of  land  which  breaks  off  seaward 
in  a  low  cliff,  apparently  formed  of  hard  clay,  Aveathering  to  a  fawn- 
color  and  thickly  studded  with  large  bowlders  which  lie  more  or  less 
definitely  in  regular  lines,  giving  a  stratified  ajipearance  to  the  whole. 
Material  of  the  same  kind  is  preserved  in  the  angle  of  the  next  bay 
nearest  to  Bold  Head.  It  Avas  also  seen  from  a  distance  to  form  the 
coast  along  the  bottom  of  the  bay  into  which  Reindeer  river  floAvs,  on 
the  ojjposite  side  of  the  entrance  of  Plover  bay,  and  again  occurs  in  tAvo 
places  on  Ennna  harbor  on  the  Avest  side,  a  little  Avithin  the  entrance  to 
the  harbor  and  at  its  southern  bay. 

The  last  named  locality  Avas  the  only  one  actually  examined  on  the 
ground.  The  deposit  is  here  bluish  gray  Avhere  freshly  exposed,  and  is 
a  rather  hard  clay  Avith  a  considerable  ]iroportion  of  coarse  sand  and 
gravel,  containing  many  boAvlders  of  somewhat  varied  lithologic 
character.  These  are  subatigular  in  form,  but  none  Avere  found  which 
actually  showed  glacial  scratching,  neither  Avere  any  shells  found  in  the 
mass.  The  deposit,  nevertheless,  undoubtedly  represents  a  species  of 
boAvlder-clay.  It  does  not  anywhere  take  the  form  of  definite  terraces, 
but  as  it  is  noAvhere  seen,  or  at  least  not  in  any  considerable  mass,  at  a 
greater  height  than  about  200  feet  above  the  sea,  Avhile  it  is  occasionally 
rather  wide  spread  l)elow  this  level,  it  may  be  assumed  as  a  whole  to 


GENERAL    REMARKS. 


143 


represent  an  ajiproximate  terrace-level,  havhig  relation  to  a  former  de- 
preasion  of  the  land  of  about  the  amount  stated. 

In  Plover  bay,  on  August  16,  large  masses  of  snow  occupied  many  of 
the  hollows,  sometimes  quite  down  to  the  edge  of  the  sea.  Portions  of 
these  accunnilations  undoubtedly  last  throughout  the  summer.  No 
glaciated  rock  surfaces  were  actually  observed,  but  this  negative  evidence 
is  here  of  small  value,  <as  it  depends  upon  observations  made  in  a  very 
short  time  and  over  a  very  small  area.  Mr  Muir  speaks  of  having  found 
glaciated  rock  surfaces  in  Plover  bay,  and  pictures  it  as  having  been  at 
one  time  filled  by  a  glacier  thirty  miles  in  length  and  from  2,000  to  3,000 
feet  in  thickness.* 


General  Remarks. 

Bering  sea  is  a  dependency  of  the  north  Pacific,  marked  olf  from  it 
by  a  bordering  chain  of  islands  like  those  which  outline  Okhotsk 
sea  and  the  sea  of  Japan.  It  differs  from  these  two  seas  by  reason  of 
its  connection  to  the  north  with  the  Arctic  ocean,  and  in  the  fact  that 
while  the  whole  eastern  part  of  its  extent  is  comparalivcsly  shallow,  the 
profounder  depths  of  the  north  Pacific  (in  continuation  of  the  Tuscarora 
deep)  are  continued  into  its  western  part.  The  Aleutian  islands,  regarded 
as  a  line  of  demarkation  between  the  nuiin  ocean  and  Bering  sea,  are 
analogous  to  the  Kurile  islands  with  Kamchatka,  and  to  the  islands  of 
Jai)an.  As  to  the  Commander  islands,  though  these  ajipear  to  lie  in  the 
continuation  of  the  arc  formed  by  the  Aleutians,  they  are  separated  by 
a  wide  and,  so  far  as  known,  very  deep  stretch  of  ocean  from  the  last  of 
these  islands,  and  it  is  wholly  pro!)able  that  they  may  re[)rescnt  an 
altogether  independent  local  elevation  analogous  to  that  to  which  Saint 
Matthew  and  it?  adjacent  islands  are  due. 

The  western  part  of  Bering  sea  has  as  yet  been  very  imi)erfectly  ex- 
plored with  the  deep-sea  lead,  but  tlie  following  general  fticts  may  be 
gathered  from  the  existing  charts :  The  entire  chain  of  the  Aleutian 
islands  is  bordered  at  no  great  distance  to  the  south  by  aliyssal  depths 
of  the  Pacific.  The  whole  western  portion  of  the  chain  likewise  slo])es 
rai)idly  down  on  the  northern  side  into  very  deep  water,  exceeding  1,000 
fathoms  as  far  to  the  eastward  as  Unimak  island ;  but  from  the  vicinity 
of  Unimak  pass  (longitude  165°  west)  the  depths  to  the  north  of  the  isl- 
ands are  consistently  less  than  100  fathoms.  Beginning  near  the  Unimak 
])ass,  the  edge  of  the  hundred-fathom  bank  runs  northwestward,  j^assing 
to  the  west  of  the  Pribilofs  and  Saint  Matthew  island  and  meeting  the 
Asiatic  coast  in  the  vicinity  of  cape  Navarin,  in  about  north  latitude  60°. 
Thus  all  jmrts  of  Bering  sea  to  the  north  and  east  of  this  line,  together 

•Report  of  the  Cruise  of  tlie  Corwln,  1881,  p.  143. 


\JL'^^''U_ 


144 


G.  ^[.  DAWSON — COASTS   Ol-'    BERING  SEA    AND    VICINITY. 


with  Bering  straits  and  much  of  the  Arctic  ocean  beyond,  must  be  con- 
sidered physiographically  as  belonging  to  the  continental  plateau  region 
and  as  distinct  from  that  of  the  ocean  basin  proper,  and  there  is  every 
reason  to  su])i)0se  that  it  has  in  later  geologic  times  more  than  once  and 
perhaps  during  prolonged  i)eriods  existed  as  a  wide  terrestrial  plain 
connecting  North  America  with  Asia. 

In  all  proliability  this  portion  of  the  continental  plateau  is  a  feature 
much  more  ancient  than  tlie  mountain  range  of  which  the  outstanding 
parts  now  form  the  Aleutian  islands.  This  range,  though  to  some  ex- 
tent due  to  U])]ift,  as  for  instance  in  the  case  of  Attn  island,  is  chiefly 
built  up  of  volcanic  materials.  Its  eastern  part,  in  the  Alaskan  penin- 
sula and  as  far  as  tlie  rniniak  pass,  must  be  regarded  as  having  been 
built  upon  the  edge  of  tlie  old  continental  plateau.  Its  western  part, 
though  certainly  the  continuation  of  the  same  line  of  vulcanism,  runs 
off  the  edge  of  the  plateau  and  rises  directly  from  the  ocean-bed. 

The  available  evidence  goes  to  show  that  the  submarine  i)lateau  of  the 
eastern  i)art  of  Bering  sea,  together  with  much  of  the  Hat  land  of  western 
Alaska,  was  covered  by  a  shallow  sea  during  at  least  the  later  part  of 
the  Miocene  period,  while  the  most  recent  jieriod  at  which  this  plateau 
stood  out  as  land  is  probably  that  at  which,  according  to  facts  previously 
noted,  the  mammoth  reached  the  Pribilof  islands  and  Unalaska  island 
across  it. 

As  to  the  date  of  the  formation  of  the  Aleutian  chain,  Dall  inclines  to 
the  belief  that  it  marks  a  line  of  weakness  or  faulting  which  has  been  in 
course  of  development  since  early  Mesozoic  times.*  This  may  be  the 
case,  but  I  have  found  nothing  on  record  nor  have  I  myself  met  with 
any  facts  which  ajipear  to  require  so  earl}'  a  date  of  origin.  The  associ- 
ation of  the  volcanic  materials  of  the  islands  in  some  cases  with  Miocene 
marine  fossils  and  with  ])lant-remains,  noted  by  Dall,  shows  that  earlj' 
in  that  period,  or  possibly  before  it,  the  islands  existed  in  some  form,  for 
the  organic  remains  are  those  of  shores  and  shallow  water,  not  of  the 
deep  sea.  The  existence  of  very  ancient  volcanic  products  forming  well 
bedded  rocks  on  Attn  island,  and  perhaps  elsewhere  in  its  vicinity,  does 
not  appear  to  have  any  necessary  connection  with  the  date  of  the  vul- 
canism to  which  the  islands  as  a  whole  are  referable,  for  such  rocks  are 
very  common  in  formations  of  many  periods  on  both  sides  of  the  Pacific, 
and  may  be  due  to  volcanic  action  along  lines  entirely  distinct  from  that 
now  occupied  by  the  Aleutians  and  long  since  extinct.  We  may  there- 
fore, I  believe,  assume  that  the  building  of  the  Aleutian  islands  began 
in  the  later  p]ocene  or  earlier  Miocene,  that  it  was  continued  with  vigor 
throughout  the  Miocene,  and  in  an  intermittent  and  declining  way  has 
survived  up  to  the  present  time. 

♦  Op.  cit.,  p.  242. 


GKNEKAL   REMARKS. 


145 


f  well 
does 
e  val- 
es are 
acific, 
that 
therc- 
tugan 
vigor 
V  has 


The  evident  marks  of  prolonged  subaerial  denudation  which  f^xist  on 
all  the  islands  of  this  chain  which  I  have  seen,  ai)i)ear  further  to  show 
that  it  has  been  long  exposed  to  such  action  since  the  main  period  of 
its  formation;  that  as  a  rule  it  has  stood  unsubmerged  since  the  Miocene, 
and  that  though  it  may  at  some  jteriod  have  been  more  elevated,  it  has 
either  not  been  more  deeply  submerged  than  it  is  at  present,  as,  if  so,  that 
such  submergence  has  endured  for  a  comparatively  very  brief  j)eriod. 

Saint  Matthew  and  its  adjacent  islands,  with  the  Commander  islands, 
appear  to  have  much  the  same  history  with  the  Aleutians,  and  may 
verj'  well  have  been  coeval  with  them  in  origin.  The  later  eruptions,  to 
which  the  Pribilof  islands  and  Nunivak  island  arc  due,  have  doubtless 
also  left  their  traces  in  the  Aleutian  chain,  while  the  volcanoes  of  Kam- 
chatka may  have  origiiiatcd  at  this  later  period  and  have  continued 
their  activity  with  little  relaxation  to  the  present  time. 

The  planes  of  marine  denudation,  noted  particularly  at  Saint  Law- 
rence island  and  at  cape  Ja{)<)unski,  on  or  near  the  western  border  of 
Bering  sea,  seem  to  reipiire  pnjlonged  stability  at  a  level  some  hundreds 
of  feet  lower  than  the  i)resent  in  that  part  of  the  region,  and  the  fact 
that  this  plane  ai)pears  to  be  caj)i)ed  by  volcanic  rocks  at  Saint  Law- 
rence island  (particularly  if  no  evidence  of  existing  volcanoes  is  found 
there),  makes  the  date  of  this  submergence  somewhat  remote.  It  may 
be  conjectured  that  it  corresponds  with  the  general  submergence  of  the 
later  Miocene.  That  the  amount  of  such  submergence  should  vary  in 
different  localities  is  quite  in  accord  with  what  might  be  expected,  per- 
haj)s,  in  any  region,  certainly  in  one  in  which  volcanic  forces  of  a  local 
kind  have  to  be  allowed  for. 

The  difference  of  climate  which  would  result  in  the  northwestern  part 
of  North  America  from  the  closing  of  Hering  strait  and  the  addition  of 
the  shallow  eastern  part  of  Bering  sea  to  the  continental  land  ma}'  not 
have  been  very  great,  inasmuch  as  the  strait  is  even  now  a  shallow  one 
and  no  very  great  volume  of  abnormally  cold  or  warm  water  flows 
through  it  in  either  direction.  The  effect  would  be  to  slightly  lower  the 
temj>erature  and  decrease  the  precij)itation  on  the  adjacent  lands.  Evi- 
dence has,  however,  recently  been  obtained  of  a  much  more  important 
factor  in  regard  to  late  changes  of  climate  in  this  region,  in  the  observa- 
tions of  Mr  L  ('.  Russell,  which  show  that  the  great  mountain  range  of 
the  Saint  Elias  alps  must  have  been  entirely  formed  in  Pliocene  or  post- 
Pliocent!  times.*  The  cruinjiling  and  upheaval  of  the  beds  which  now 
form  this  range  must  have  relieved  a  notsible  and  accumulating  tangen- 
tial pressure  of  the  earth's  crust,  the  result  of  which  it  is  yet  dilHcult  to 
trace ;  but  that  it  must  have  brought  about  extensive  changes  of  level 

♦  National  Geographic  Mugiiisine,  Wnsliinglon,  p.  174.    Hull.  U.  S.  Gool.  Surv.,  no.  84,  p.  259. 


146 


a.  M.  DAWSON — COASTS   OP   BERIKG    SEA    AND   VIOINITY. 


I'    ' 
I  i 


throughout  the  region  over  which  this  pressure  was  exerted  seems  cer- 
tain, and  I  am  inclined  to  8U])pose  that  it  may  luive  had  much  to  do 
with  the  great  later  Pliocene  uplift  and  subseciuent  depression  to  which 
the  British  Columbian  region  ap])cars  to  have  been  subjected* 

One  of  the  most  remarkable  features  connected  with  the  Bering  sea 
region  is  the  entire  absence  of  any  traces  of  a  general  glaciation.  State- 
ments to  the  effect  that  Alaska,  as  a  whole,  showed  no  such  traces  were 
early  made  by  Pall  f  and  concurred  in  by  Whitney.  The  result  of  mj' 
later  investigations  in  British  Columbia  and  along  the  adjacent  coasts 
have  been  to  show  that  such  original  statements  were  altogether  too  wide; 
that  a  great  Cordilleran  glacier  did  exist  in  the  western  part  of  the  con- 
tinent, but  that  it  formed  no  i)art  of  any  hypothetical  polar  ice-cap,  and 
that  large  portions  of  northwest  America  lay  beyond  its  borders.J 

Statements  made  by  Mr  John  Muir,  in  which  he  not  only  attributed 
every  physical  feature  noted  by  him  in  Bering  sea  to  the  action  of  glacia- 
tion, but  even  expressed  the  opinion  that  Bering  sea  and  strait  repre- 
sented a  hollow  produced  by  glaciation,  §  remain  altogether  unsupported. 
It  might  be  unnecessary  even  to  refer  to  them  but  for  the  fact  that  they 
relate  to  a  region  for  which  the  data  on  this  subject  from  other  sources 
are  so  small.  No  traces  have  been  found  of  general  glaciation  by  land 
ice  in  the  region  surrounding  Bering  sea,  while  the  absence  of  erratics 
above  the  actual  sealine  show  that  it  was  never  submerged  for  any  length 
of  time  below  ice-encumbered  waters. 

These  facts,  moreover,  connect  themselves  with  similar  ones  relating  to 
the  northern  parts  of  Siberia  in  a  manner  which  will  be  at  once  obvious 
to  any  student  of  the  glacial  period. 

RcLpecting  the  latest  changes  in  elevation  of  the  land,  it  may  be  stated 
that  in  several  widely  separated  places  there  is  evidence  of  a  recent  slight 
general  uplift.  This  was  noted  at  Unalaska,  Attu,  Bering  island.  Saint 
Paul  island  and  Saint  Matthew  island,  but  the  amount  of  elevation  indi- 
cated is  small,  being  in  fact  from  10  to  30  feet  only. 

♦  Trans.  Royal  Soe.  Cniinda,  vol.  vli,  sec.  iv,  p.  54. 

t  Alaska  Coast  Pilot,  1809,  pp.  195,  19(1;  Alaskii  and  its  Resources,  pp.  iW,  461. 
IQuart.  Journ.  Gool.  Soc,  vol.  xxxiv,  p.  119;  vol.  xxxvii,  p.  28.1;  Report  of  Progress,  Geol  Siirv. 
Can.,  1877-78,  pp.  13(1  B,  1,51  B;  Trans.  Royal  Soc.  Ciinnda,  vol.  vii,  soc.  iv,  plate  ii,  map  4. 
i  Report  of  the  Cruise  of  the  Corwin,  1881,  p.  147. 


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